1. Motion, Forces and Energy Flashcards

Question

What does the gradient of a distance-time graph represent?

Answer 1

Acceleration

Answer 2

Negative acceleration

Answer 3

Constant at 10 m/s

Answer 4

The amount of matter contained in an object

Answer 5

A gravitational force

Answer 6

Change in motion or change in direction

Answer 7

1. In the absence of air resistance, all objects fall with the same acceleration, regardless of their mass 2. So long as air resistance remains insignificant, the speed of a falling object will increase at a steady rate, getting larger the longer it falls for.

Answer 8

1. There is a downwards unbalanced force and the skydiver accelerates 2. As the skydiver speeds up, the air resistance increases 3. Eventually the air resistance balances the weight and so the skydiver travels at a constant speed 4. When the parachute is opened the increase air resistance on the parachute creates an upwards unbalanced force, making the parachuting to slow down

Answer 9

Terminal velocity

Answer 10

Using a balance

Answer 11

ρ = mass ÷ volume

Answer 12

The less dense object will float on a more dense object

Answer 13

Change in size Change in motion Change in direction

Answer 14

The extension of a spring is proportional to the applied force

Answer 15

F = kx *where k is the spring constant

Answer 16

Point at which load and extension are no longer proportional

Answer 17

Point at which the spring will no longer return to its original position after being stretched

Answer 18

A relationship is said to be proportional if the graph is a straight line going through the origin. If a graph is a straight line but does not go through the origin the relationship is said to be linear.

Answer 19

An object at steady speed in circular orbit is always accelerating as it’s changing direction but gets no closer to the center

Answer 20

A force acting at 90 degrees to an object’s direction of travel

Answer 21

Mass Speed Radius

Answer 22

A greater mass requires greater force

Answer 23

A greater speed requires greater force

Answer 24

A greater radius requires greater force

Answer 25

A force acting towards the centre of a circle

Answer 26

1. Continues to travel at constant speed in a straight line 2. Stays at rest

Answer 27

The force between two surfaces which impedes motion and results in heating

Answer 28

Air resistance

Answer 29

A measure of the turning effect of a force

Answer 30

1. Increasing force 2. Increasing distance from a pivot

Answer 31

Nm = Force × perpendicular distance from the pivot

Answer 32

For a system to be balanced, the sum of clockwise moments must be equal to the sum of anticlockwise moments

Answer 33

1. No resultant force 2. No turning effect

Answer 34

The point through which the weight of an object acts

Answer 35

The point of symmetry

Answer 36

Make a hole in the lamina Hang it so it can swing freely Hang a plumb line in the hole Use a pencil to draw a vertical line from the pivot Repeat the process, suspending the object from a different point Centre of mass is locating where the lines cross

Answer 37

When its centre of mass lies above its base

Answer 38

When its centre of mass does not lie above its base

Answer 39

A lower centre of mass will make the object more stable

Answer 40

1. Increase surface area 2. Make the object shorter

Answer 41

A quantity with only magnitude

Answer 42

A quantity with both magnitude and direction

Answer 43

Distance, time, energy and mass

Answer 44

Acceleration, momentum, displacement and force

Answer 45

Draw an arrow representing the first vector Starting at the tip of the first vector, draw an arrow representing the second vector Resultant vector is found by going from the tail of the first vector to the tip of the second vector

Answer 46

p = mass × velocity (or) mv

Answer 47

1. impulse = force × time 2. impulse = change in momentum / Ft = mv - mu

Answer 48

In the absence of external forces, the total momentum of a system remains the same

Answer 49

Kinetic Gravitational potential Internal Elastic (strain) Chemical Nuclear

Answer 50

kinetic energy = 0.5mv^2

Answer 51

gravitational potential energy = mg∆h

Answer 52

Energy cannot be created or destroyed, it can only change from one form to another

Answer 53

The capacity of something to do work

Answer 54

Forces (mechanical working) Electrical currents (electrical working) Heating Waves

Answer 55

Heat, sound and light

Answer 56

Fuels are burnt to produce heat Heat is used to convert water into steam Steam turns turbines Turbines generate electricity

Answer 57

Hydroelectric and tidal power use GPE of water This turns turbines Turbines generate electricity

Answer 58

1. Kinetic energy of waves is used to turn turbines 2. Turbines generate electricity

Answer 59

Heat from underground rocks used to generate steam Steam turns turbines Turbines generate electricity

Answer 60

Uranium atoms split by firing neutrons at them Releases heat used to generate steam Steam turns turbines Turbines generate electricity

Answer 61

Photovoltaic cells use light to generate electricity

Answer 62

Heat is used to warm water moving through black pipes Steam is produced to turn turbines Turbines generate electricity

Answer 63

1. Kinetic energy of wind used to turn wind turbines 2. Wind turbines generate electricity

Answer 64

Cost-effective Produce energy on a large-scale Reliable

Answer 65

1. Produces greenhouse gases 2. Non-renewable

Answer 66

Renewable No greenhouse gases produced Produces energy on a large-scale Hydro is reliable

Answer 67

1. Expensive to build 2. Tidal is not reliable

Answer 68

1. Reliable 2. Cost-effective

Answer 69

1. Does not produce energy on a large-scale 2. Produces greenhouse gases 3. Non-renewable

Answer 70

1. Reliable 2. Produces energy on a large-scale 3. No greenhouse gases produced

Answer 71

1. Produces radioactive waste 2. Expensive to build

Answer 72

1. Renewable 2. No greenhouse gases produced

Answer 73

1. Unreliable 2. Does not produce energy on a large-scale 3. Expensive to set up

Answer 74

1. Geothermal 2. Nuclear 3. Tidal

Answer 75

1. Geothermal 2. Nuclear 3. Tidal

Answer 76

Nuclear fusion

Answer 77

How much useful work is done from the total energy supplied

Answer 78

Efficiency = useful energy output ÷ total energy input

Answer 79

Efficiency = useful power output ÷ total power input

Answer 80

Energy transferred

Answer 81

1. Magnitude of the force 2. Distance moved in the direction of the force

Answer 82

W = Fd = ∆E

Answer 83

Joules (J) or Newtonmetres (Nm)

Answer 84

Amount of energy transferred per second

Answer 85

P = ∆E/t

Answer 86

The concentration of a force

Answer 87

Mercury barometer

Answer 88

Extra pressure the gas supply has

Answer 89

1. Depth of the liquid 2. Density of the liquid

Answer 90

For a fixed mass of gas at constant temperature, the pressure is inversely proportional to volume

Answer 91

Up thrust is created when an object displaces a fluid, such as a boat displacing water. Reaction force is the upward force on a block which is resting on a solid surface.

Answer 92

newton or N

Answer 93

magnetic force This force can be attractive or repulsive

Answer 94

W=mg W = 100 kg x 10 N/kg W = 1000 N

Answer 95

gradient of velocity-time graph

Answer 96

Gravitational force

Answer 97

The object is accelerating or speeding up from the starting position The gradient of the line is increasing, therefore velocity is increasing.

Answer 98

More steep line Object is covering more distance per time

Answer 99

50 N - 50 N = 0

Answer 100

metre or m

Answer 101

acceleration force velocity

Answer 102

gradient of the line is the steepest more distance covered per time faster speed

Answer 103

-gradient of the line is negative -velocity is negative -travelling in opposite direction to part A

Answer 104

average speed = total distance travelled/ time taken

Answer 105

Thrust Thrust is created when an object throws something out in one direction- such as gases.

Answer 106

air resistance

Answer 107

gradient of velocity-time graph

Answer 108

area under a velocity-time graph

Answer 109

in the graph, that gradient is getting less steep

Answer 110

change the speed of the object (accelerate or decelerate) change the direction of the object change the shape of the object

Answer 111

constant velocity, no acceleration

Answer 112

That the object is not moving, has zero speed

Answer 113

downward gravitational pull (or weight) upward reaction force from table

Answer 114

It will gain 10 metres per second every second. After 10 s if should be travelling at 100 m/s!

Answer 115

gradient of distance-time graph

Answer 116

use oil or grease on the surfaces make the surfaces smoother blow air between the surfaces

Answer 117

Gradient that is zero therefore speed is zero- object is not moving

Answer 118

metre per second squared or m/s2

Answer 119

gravity g is measure in N/kg It is the force which acts on every kg of mass

Answer 120

A –> B velocity is constant B –> C velocity is zero C –> D velocity is increasing D –> E velocity is zero E–> F velocity is constant but opposite direction

Answer 121

A force meter

Answer 122

Acceleration is the rate of change of speed OR The change in speed per unit time

Answer 123

in the graph the gradient is constant throughout

Answer 124

time mass speed distance energy

Answer 125

Weight = mass x gravitational field strength W = mg

Answer 126

The gradient of the line is increasing speed is increasing object is accelerating

Answer 127

seconds or s

Answer 128

F = ma An object will accelerate or decelerate if an unbalanced force is acting on it. F is the resultant force

Answer 129

dots are evenly spaced object is covering the same distance per unit time object is travelling at a constant speed, it is not accelerating

Answer 130

dots are evenly spaced object is covering the same distance per unit time object is travelling at a constant speed, it is not accelerating

Answer 131

metre per second or m/s

Answer 132

metre per second or m/s

Answer 133

gradient is getting less steep

Answer 134

electrostatic force This can be attractive or repulsive

Answer 135

scalar quantities have magnitude only vector quantites have both magnitude and direction

Answer 136

Calculate the gradient of the line at that instant. Draw a triangle and calculate speed = rise/ run - distance travelled/ time

Answer 137

gradient of distance-time graph

Answer 138

W=mg W = 100 kg x 10 N/kg W = 1000 N

Answer 139

distance = speed x time

Answer 140

dots are moving further apart object is cover more distance per unit time object is speeding up, accelerating

Answer 141

dots are moving further apart object is cover more distance per unit time object is speeding up, accelerating

Answer 142

Mass is the amount of matter an object is made of (measured in kg or g) Weight is the gravitational pull on the object which depend on the gravitational field strength of the planet (measured in Newtons or N)

Answer 143

The moon has less mass than the Earth

Answer 144

100 kg Mass the amount of matter an object is made of. It does not change when on another planet

Answer 145

dots are evenly spaced object is covering the same distance per unit time object is travelling at a constant speed, it is not accelerating

Answer 146

dots are evenly spaced object is covering the same distance per unit time object is travelling at a constant speed, it is not accelerating

Answer 147

dots get closer together, then further apart object is covering less distance per unit time, then more distance per unit time. object is slowing down then speeding up, decelerating, then accelerating

Answer 148

dots get closer together, then further apart object is covering less distance per unit time, then more distance per unit time. object is slowing down then speeding up, decelerating, then accelerating

Answer 149

dots get closer together object is covering less distance per unit time object is slowing down

Answer 150

Weight will be 1/6th that on the Earth which is 100N To calculate mass on Earth W= mg m = W/g mass = 600 / 10 = 60 kg Mass on the moon is the same- 60kg

Answer 151

gradient is zero

Answer 152

Force = mass x acceleration F = ma This is called Newton’s second law

Answer 153

dots are moving further apart object is covering more distance per unit time object is speeding up, accelerating

Answer 154

Gradient is zero therfore speed is zero- obejct is not moving

Answer 155

magnetic force

Answer 156

dots get closer together, then further apart object is covering less distance per unit time, then more distance per unit time. object is slowing down then speeding up, decelerating, then accelerating

Answer 157

time = distance / speed

Answer 158

a = (v-u)/t OR a = change in velocity / time

Answer 159

The arrow length can represent the magnitude of the force. The arrow direction can represent the direction the force is acting in.

Answer 160

100 kg Mass the amount of matter an object is made of. It does not change when on another planet

Answer 161

It will lose 2 metres per second every second. after 4 seconds it will decrease its velocity by 8 m/s 14 - 8 = 6 m/s

Answer 162

the mass per unit volume

Answer 163

Read the volume at eye level and to the bottom of the meniscus place measuring cylinder on a level surface

Answer 164

g/cm^3 or kg/m^3

Answer 165

First orientation P = F/A The second block has a larger area in contact with the table, for the same force, therefore, the pressure is lower

Answer 166

1. Half fill measuring cylinder with water and read initial volume at eye level and bottom of the meniscus 2. lower object into measuring cylinder- make sure that it is fully submerged and water level has not risen above the scale 3. read final volume at eye level and bottom of the meniscus 4. Volume of object = final volume - initial volume

Answer 167

density = mass / volume if mass is double for the same volume, the density doubles. density is proportional to mass

Answer 168

1. measure the mass of 50 paperclips on a balance 2. half fill a measuring cylinder with water and record initial volume 3. carefully add 50 paperclips and record final volume. 4. calculate the volume by taking the difference 5. Find density = mass / volume

Answer 169

1 Pascal = 1 Newton per metre square

Answer 170

calculate the gradient gradient = rise/run = mass/volume

Answer 171

A sharp knife with a small surface area creates a greater pressure for the same force. pressure = force/area The knife will cut more easily

Answer 172

ρ = mass ÷ volume

Answer 173

ρ = mass ÷ volume

Answer 174

Newton or N

Answer 175

Camels feet have a large surface area P = F/A A larger surface area for the same force results in lower pressure The camel will not sink as much in the sand and can walk more easily.

Answer 176

1. overfill eureka can with water and wait for water to stop dripping from the spout 2. hang object from a string and slowly lower the object into the water 3. make sure that the object is fully submerged

Answer 177

Second orientation P = F/A The second block has a smaller area in contact with the table for the same force, therefore, the pressure is higher

Answer 178

Second orientation P = F/A The second block has a smaller area in contact with the table for the same force, therefore, the pressure is higher

Answer 179

Their densities are the same. Both the mass and the volume were halved.

Answer 180

The pressure on both dams is the same since the depth of water is the same

Answer 181

Pascal (Pa)

Answer 182

Pascal (Pa)

Answer 183

P = density x gravity x depth All the sections experience the same pressure since the depth of water is the same. Pressure at depth is not affected by the volume of water- only the depth of water above it.

Answer 184

Ice has less particles per unit volume ice has a lower density Ice floats on sea water

Answer 185

placed balance on level surface tare (zero) balance before use

Answer 186

As depth double, pressure doubles. Pressure is proportional to depth The graph is a straight line through the origin.

Answer 187

kg always convert grams to kilograms

Answer 188

Air particles move in all directions and collide with objects Air particles move fast and freely Air pressure is related to the depth of air over the object.

Answer 189

m^2 or cm^2

Answer 190

Object that has more mass per unit volume - the gradient is steeper

Answer 191

First object Greater mass per unit volume The particles are more closely packed

Answer 192

First object Greater mass per unit volume The particles are more closely packed

Answer 193

Answer: 2) weaker spring B has a smaller gradient It requires less force to stretch by the same amount.

Answer 194

It has a low centre of gravity The weight acts from the centre of gravity.* It will not tip until the weight goes beyond the base*

Answer 195

portion c and e The velocity is constant. The graph is horizontal at c and e gradient is zero = zero acceleration or constant speed The parachutist has reached terminal velocity at c and again at e (after he opens his parachute)

Answer 196

Draw lines of symmetry to find the centre of the object.

Answer 197

The wire obeys Hooke’s Law during the straight part of the graph. If the force were removed, the wire behaves elastically and would go back to its original length. For larger forces the wire no longer obeys Hooke’s Law, the wire behaves plastically and will not go back to its original length.

Answer 198

Thinking distance is the distance a car travel after you see the hazard to the point you put your foot on the brake - the distance travelled while you are reacting to the hazard

Answer 199

Swung to one side, the line of the weight (the force) does not act through the pivot at the top of the hanger. M= F x d, there is a moment about the pivot making it swing. When at rest the line of the weight (the force) acts through the pivot at the top of the hanger. M = F x d. there is no moment about the pivot. No longer swings.

Answer 200

The point on an object where the weight appears to act.

Answer 201

There are three springs in the series system. Each spring will stretch 10 cm. The total stretch of the series spring system would be 30 cm.

Answer 202

tiredness drinking or drug taking speed of vehicle distractions such as mobile phone

Answer 203

The distance a vehicle travels while the brakes are applied and the vehicle comes to rest.

Answer 204

The centre of gravity of the elephant is located over the ball The weight of the elephant passes through the ball (base) There is no perpendicular distance to the pivot and no moment (turning effect)

Answer 205

stopping distance = thinking distance + braking distance

Answer 206

As speed double the braking distance more than doubles- it actually quadruples!

Answer 207

There are two springs in series with 2 N hanging on them. They will both stretch by 10 cm. The overall stretch will be 20 cm.

Answer 208

There are two springs in series with 2 N hanging on them. They will both stretch by 10 cm. The overall stretch will be 20 cm.

Answer 209

Spring A needs more force to stretch the same distance as spring B. Gradient for spring A is greater.

Answer 210

Moment = force x perpendicular distance

Answer 211

tread depth of tyres icy or wet roads mass of vehicle condition of brakes speed of vehicle

Answer 212

For an object to be in equilibrium sum of the clockwise moments must equal the sum of the anticlockwise moments

Answer 213

W = mg Weight = mass x acceleration

Answer 214

Read the length at 0 N Therefore the original length is 15.0 cm extension = length - original length. extension = 40.0 - 15.0 = 25.0 cm

Answer 215

Read the length at 0 N Therefore the original length is 15.0 cm extension = length - original length. extension = 40.0 - 15.0 = 25.0 cm

Answer 216

1- punch three holes along edge of the lamina hang the lamina on a horizontal pin in a cork hang plumbline infront of lamina let the lamina and plumbline come to rest mark plumbline position down the lamina repeat for other two holes. centre of gravity is located where all three lines cross.

Answer 217

The object will turn Moment is a vector quantitiy and there will be a resultant moment

Answer 218

The gradient of the graph is decreasing. gradient of a v-t graph is the acceleration acceleration is decreasing

Answer 219

0.2 m is the perpendicular distance to the line of force. OR 0.3 m is not perpendicular to the force

Answer 220

As speed doubles, thinking distance doubles- you cover double the distance in the same reaction time.

Answer 221

read the length of the spring at eye level to avoid a parallax error allow spring to stop bouncing up and down before taking reading. repeat readings AND take an average by taking readings as the spring is loaded then again as it is unloaded- do not go beyond its elastic limit.

Answer 222

The straight region of the graph shows that the force is proportional to the extention. Therfore, it obeys Hooke’s Law If the spring is stretched beyond the elastic limit it would no longer go back to its original length.

Answer 223

The straight region of the graph shows that the force is proportional to the extention. Therfore, it obeys Hooke’s Law If the spring is stretched beyond the elastic limit it would no longer go back to its original length.

Answer 224

portion d The velocity is decreasing at d and the gradient is very steep representing a very large deceleration.

Answer 225

wire must be over 1 metre attach tape to wire with a pen line- read length at eye level add mass carefully to wire without pulling on it

Answer 226

The force exerted The perpendicular distance between the line of action (force) and the pivot. Moment = Force x perpendicular Distance

Answer 227

There are two springs in parallel. Each spring needs 6N to stretch 20 cm. The overall force needed is 12 N to stretch the parallel system 20 cm

Answer 228

Boy > teenager > woman > man The man has the highest centre of gravity* The boy has the lowest centre of gravity*

Answer 229

The spring will stretch 2x centimetres. Springs obey Hooke’s Law.* If force is doubled, extension doubles.* Force is proportional to extension*

Answer 230

M clockwise = 200 N x 40 cm = 800 Ncm To be at equilibrium, sum of clockwise moments must equal the sum of the anticlockwise moments M anticlockwise = F x 100 cm = 800 Ncm Force of 8 N needed!!

Answer 231

M clockwise = 5 N x 0.5 m = 2.5 Nm To be at equilibrium, sum of clockwise moments must equal the sum of the anticlockwise moments M anticlockwise = F x 0.25 = 2.5 Ncm Force of 10 N needed!!

Answer 232

at the start- only downward weight is acting on the person. Large resultant force downward. F=ma, large force –> more acceleration as speed increases at b, air resistance increases. Resultant force is smaller, F=ma, smaller force, less acceleration at c- upward air resistance = downward weight. Forces are balanced. Resultant force = zero, F=ma, no resultant force, no acceleration- constant speed and terminal velocity has been reached

Answer 233

B It has the largest perpendicular distance to the pivot. Moment = Force x perpendicular distance to the pivot Both A and C have a zero perpendicular distance to the pivot

Answer 234

The force extension graph for the rubber band is not a straight line through the origin. Force is not proportional to extension It does not obey Hooke’s Law

Answer 235

The force extension graph for the rubber band is not a straight line through the origin. Force is not proportional to extension It does not obey Hooke’s Law

Answer 236

The force-extension graph is a straight line through the origin. As the force doubles the extension doubles Force is proportional to extension

Answer 237

velocity = displacement/ time

Answer 238

vector quantity direction matters!! A clockwise moment can cancel an anticlockwise moment.

Answer 239

it travels in straight lines it can travel through a vacuum it can reflect off surfaces it is an electromagnetic wave much like light it travels at the speed of light it is a transverse wave

Answer 240

1000 J = one large square 200 J = each small square Useful transfer of Energy Out = 9 small squares 1800J of energy useful transferred electrically out of thermal power station 1800 J/ 5000J = (3600/ 10 000J) x 100 = 36%

Answer 241

1000 J = one large square 200 J = each small square Useful transfer of Energy Out = 9 small squares 1800J of energy useful transferred electrically out of thermal power station 1800 J/ 5000J = (3600/ 10 000J) x 100 = 36%

Answer 242

battery coal- fuel food

Answer 243

Uranium in a nuclear power station Fusion occurring in the Sun

Answer 244

Liquids and gases have particles which are further apart and have weak forces between them- poor conductors Liquid and gases have particles can move freely Convection occurs when particles gain energy (heat up) expands and move from hot to cold regions

Answer 245

Gravitational store of the roller coaster is being depleted Kinetic store of the roller coaster is being filled along with the thermal store of the track, wheels and surroundings. Energy is also shifted/transferred away via radiation of sound

Answer 246

Conduction occurs when heat is transferred through a material from particle to particle Metals have free electrons which help heat transfer through the metal from particle to particle

Answer 247

Energy cannot be created nor destroyed, only transferred from one store to another.

Answer 248

Gravitational store of water is depleted This is transferred mechanically to the kinetic store of the water via the force of gravity

Answer 249

Conduction from the stove to the metal pan- they are in contact Conduction through the metal pan Conduction from the pan to the water- they are in contact Convection to the potato- hot water expands (is less dense) and rises Conduction through the potato

Answer 250

you need a large area and a large number to replace one power station it is not reliable- no wind, no power they are a danger to birds on land and boats if in the sea they are loud and some say unsightly

Answer 251

Conduction occurs when heat is transferred through a material from particle to particle In solids, the particles are close together and the forces between particles are stronger.

Answer 252

non-renewable source creates radioactive waste which takes thousands of years to decay to a safe level expensive to build, maintain and decommission the possibility of a meltdown causing environmental damage

Answer 253

The thermometer on the left nearest the matt black surface. The hot metal radiates heat to the surroundings but the matt black surface will radiate heat at a quicker rate.

Answer 254

they are reliable- produce a constant supply much of the existing infrastructure is set-up for fossil fuels at the moment fossil fuels are relatively cheap

Answer 255

by heating

Answer 256

renewable energy source does not use fossil fuels does not produce carbon dioxide or other pollutants

Answer 257

Conservation of energy is energy cannot be created nor destroyed, it is only transferred from one store to another. 100kJ = Energy In 4kJ + 63kJ + ? = Energy Out 33kJ of energy goes to respiration in the cow

Answer 258

Conservation of energy is energy cannot be created nor destroyed, it is only transferred from one store to another. 100kJ = Energy In 4kJ + 63kJ + ? = Energy Out 33kJ of energy goes to respiration in the cow

Answer 259

Usefully- Electrically via wires Wastefully- Heating from furnace, wires and cooling towers Radiated as sound from generator Radiated as light from furnace

Answer 260

car, moving spaceship, moving bullet moving generator turning

Answer 261

The fleece traps air air is a poor conductor- reduces heat loss by conduction air cannot move- no convection currents set up- reduces heat loss by convection

Answer 262

flooding of valleys and loss of habitats can only be built in areas which are mountainous. flooding of valleys and displacement of communities expensive to build

Answer 263

Electrically- charge moves in wires

Answer 264

The matt black container Matt black surfaces are good absorbers of heat radiation Shiny silvery surfaces will reflect heat radiation

Answer 265

hot pan hot water in a kettle the filament in a toaster a human body

Answer 266

Chemical Thermal Gravitational Kinetic Vibrational Nuclear Electrostatic & magnetic Elastic

Answer 267

mechanically- elastic exerts a force on the stone Elastic store of elastic is emptied* Kinetic store of stone is filled*

Answer 268

Elastic store of popper toy is depleted Kinetic store of popper toy is filled This energy is transferred mechanically via a spring force

Answer 269

Energy is wastefully shifted/transferred from the wind turbine via radiation (sound) and heating from wires and generator

Answer 270

Chemical store

Answer 271

Electrostatic Two similarly charged particles near each other Charged van de Graaf generator Magnetic North and north pole of a magnet pushed together North pole of a magnet and south pole of an electromagnet pulling in a speaker cone

Answer 272

Efficiency = useful energy output ÷ total energy input Efficiency = useful power output ÷ total power input

Answer 273

mechanically from gravitational store of water to the kinetic store of the water mechanically from the turning turbine to the turning generator electrically from the turning generator via the wires to the nearby town

Answer 274

Via radiation through space (EM radiation) Electrically through wires from solar cell

Answer 275

Water behind a dam Person at the top of a slide Spaceship in orbit around Earth

Answer 276

independent- I change dependent- what you measure Independent variable - type of material wrapped around the copper can Dependent variable- temperature difference of water after a set amount of time

Answer 277

Solar cells convert energy transferred by radiation (light) into energy transferred electrically Solar panels convert energy transferred by radiation into the thermal store of water

Answer 278

mechanically- elastic exerts a force on the stone Elastic store of elastic is emptied* Kinetic store of stone is filled*

Answer 279

Kinetic store of the wind

Answer 280

Gravitational store

Answer 281

Mechanically- there is a force on the turbine which makes it turn

Answer 282

Control variables- what is kept the same to keep a fair test. volume of water- all 100ml initial temperature of water- all 90°C thickness of material- all 5mm type of can- all copper metal with the same thickness lid- all containers have a lid of same thickness and material same type of liquid- water

Answer 283

renewable energy source- does not use fossil fuels does not produce CO2 or pollutants reliable- energy transferred at a constant rate can be turned off when not needed the lake created behind the dam can be used for sport and recreation

Answer 284

Energy is shifted mechanically by the force of gravity

Answer 285

Nuclear store of the uranium is being depleted. The energy is transferred electrically to the nearby town.

Answer 286

Thermal store

Answer 287

Kinetic store of popper toy is depleted Gravitational store of popper is filled Energy is transferred mechanically via the force of gravity

Answer 288

flooding of valleys and loss of habitats flooding of valleys and displacement of communities expensive to build

Answer 289

eff = useful energy out / total energy in 36J/50J = (72/100) x 100 = 72% 28% of energy is wasted as thermal store of the surroundings

Answer 290

does not produce carbon dioxide- a greenhouse gas does not use fossil fuels reliable continuous supply of electricity

Answer 291

Elastic store of popper toy is depleted Kinetic store of popper toy is filled This energy is transferred mechanically via a spring force

Answer 292

stretched elastic in a catapult bent ruler stretched spring in a clockwork toy

Answer 293

Nuclear store is being depleted (emptied) Energy is shifted or transferred away from the sun by radiation (infrared, visible light UV etc…)

Answer 294

Nuclear store is being depleted (emptied) Energy is shifted or transferred away from the sun by radiation (infrared, visible light UV etc…)

Answer 295

The matt black side will radiate the most heat The shiny silvery side will radiate the least heat

Answer 296

using graph paper create a scale- e.g. one small square = 10J If Total Energy In is= 200J arrow should be 20 squares in width to start. Useful Energy Out - straight arrow forward 5 squares = 50J -Wasted Energy Out -arrow curling downward 15 squares = 150J

Answer 297

renewable no polluting gases produced reliable- we know when the tides occur saves fossil fuels

Answer 298

renewable does not produce harmful gases a free energy source does not use fossil fuels

Answer 299

not reliable- no waves, no energy can only be built for countries with coastal regions a danger to boats/ships you need a large number to replace one power station

Answer 300

mechnically- by a force electrically- movement of charge radiation- light or sound heating- hot to cold

Answer 301

air above the radiator is heated hot air expands and becomes less dense hot air rises and moves along the ceiling hot air cools (becomes denser) and falls cool air is pulled towards radiator to replace hot air which moved upward

Answer 302

Chemical store of biomass is transferred via heating when biomass is burnt This is mechanically transferred to a turbine which is mechanically transferred to a generator The kinetic store of the generator turning is transferred electrically to the wires.

Answer 303

they are expensive they are inefficient they are not reliable- less sun, less power

Answer 304

can only be built where the Earth’s crust is thin- limited places high initial set-up costs very high temperatures needed to produce power- need to produce steam, not just hot water.

Answer 305

Nuclear store of the uranium is being depleted. The energy is transferred electrically to the nearby town.

Answer 306

heating from the reactor, turbines, generator and wires radiation of sound from turbines and generators.

Answer 307

does not use fossil fuels renewable does not produce carbon dioxide or other pollutants

Answer 308

Thermal store of surroundings (air, table etc)

Answer 309

Conduction occurs when heat is transferred through a material from particle to particle

Answer 310

Chemical store the match is emptied. This energy is shifted/transferred away from the match by radiation (light) and heating to the surroundings. The thermal store of the surrounding is being filled

Answer 311

The stopper prevents heat escaping by convection. The vacuum prevents heat escaping by conduction. The inner flask is reflective inside, so it reduces heat lost by radiation. The outer case protects the inner flask, and add another layer of insulation

Answer 312

Gravitational store of the water is depleted and kinetic store of water is filled.

Answer 313

The cup at 80°C will radiate the most heat to the surroundings. The greater the temperature difference the greater the rate of heat transfer.

Answer 314

fossil fuels are non-renewable when they burn they release carbon dioxide which is a greenhouse gas when they burn they produce sulfur dioxide which creates acid rain

Answer 315

Lid stops heat loss by convection- lid traps air and does not allow it to move, no convection currents created which carries heat energy away Vacuum stops heat loss by conduction- no particles means heat cannot be transferred from particle to particle through the walls to the outside Shiny surface stops heat loss by radiation as shiny silvery surfaces reflect heat radiation back into the flask.

Answer 316

Kinetic store of the blades are filled Their energy is usefully transferred mechanically to the kinetic store of the generator Energy is usefully shifted/transferred from the generator electrically

Answer 317

it is renewable once set-up it is free does not produce pollutants- no harmful gases produced

Answer 318

A solar furnace consists of a large number of mirrors which reflects the sun’s radiation to one point. At this focal point is a pipe with water. The radiative energy (light) heats the water and creates steam. Steam turns a turbine, which turns a generator producing electricity.

Answer 319

You need an estuary- limited places to build it disrupts the movement of boats/fish etc.. not constant power, times of day where less power is given out

Answer 320

The heatproof mat is an insulator It reduces heat loss by conduction to the table below Conduction occurs when heat is transferred from particle to particle when objects are in contact.

Answer 321

Can change: Shape Direction of travel Speed

Answer 322

Weight Gravitational Friction Air resistance (drag) Tension Up thrust Reaction force

Answer 323

Lower mass object

Answer 324

if the forces on an object are balanced, the object will: 1. Continue travelling at a constant velocity 2. Or if stationary -> will remain stationary

Answer 325

Resultant force= mass x acceleration F= ma

Answer 326

Lubrication eg oil for friction Streamlined design for air resistance

Answer 327

Brakes on a car

Answer 328

What is an example of unuseful friction/

Answer 329

If A exerts a force on B, then B exerts the same force on A but in the opposite direction

Answer 330

The amount of matter contained in an object

Answer 331

Force of gravity acting on an object

Answer 332

Weight = mass x gravitational field strength W = mg

Answer 333

Force between objects that have mass

Answer 334

Thrust = constant Mass = decrease Weight = decrease Resultant force = increase Acceleration = increase Velocity = increase

Answer 335

Weight In the absence of air resistance all objects will fall with an acceleration equal to gravity

Answer 336

weight which remains constant - air resistance that increases with speed

Answer 337

1. As parachutist jumps: - only force acting = weight - air resistance = 0 - acceleration 2. Then: - air resistance increases as speed increases - resultant downwards force decreases (cos more upwards force) - acceleration thus decreases 3. Terminal velocity: - air resistance reaches a maximum + is equal to weight - resultant force is 0N - acceleration = 0 - travels at constant velocity (terminal velocity)

Answer 338

1. Parachutist at terminal velocity : - resultant force + acceleration = 0 - constant velocity 2. Opens chute: - air resistance increases + resultant force is in negative direction - thus large deceleration - still moves down 3. As it slows, air resistance decreases until air resistance = weight - resultant force = 0 and acceleration = 0 - new slower terminal velocity

Answer 339

Investigate relationship between force and extension

Answer 340

1. Set up apparatus 2. Record initial length of spring (should subtract this from all further measurements to find extension) 3. Add 100g mass to spring 4. Record mass and new length of spring 5. Add another 100g mass to spring 6. Record new mass and new length of spring 7. Repeat 8. Remove all masses and repeat 3 times and take mean average of extension 9. Calculate the force by multiplying the mass x gravity 10. Plot graph force x extension

Answer 341

The extension of a spring is directly proportional to the applied load force

Answer 342

Force extension graph will be a straight line through the origin If the force doubles the extension doubles Force divided by extension is constant

Answer 343

When the stretching force is removed the object will return to its original shape

Answer 344

goggles in case spring snaps stand up so no feet are under masses g clamp to secure clamp stand to desk so that it does not fall over

Answer 345

F= kx (where F = force, k = spring constant, x = extension) Constant= F/x (stiffness of spring) Thus if you double the force, you double the extension (because k is always constant)

Answer 346

make sure measurements with ruler are taken at eye level to avoid parallax error

Answer 347

When the stretching force is removed the object will not return to its original shape, it will be permanently deformed

Answer 348

The spring constant

Answer 349

wont return to its original shape - unloading extensions will be larger than the loading extensions

Answer 350

N/m not Nm! Which is unit for moment

Answer 351

Turning effect around a pivot

Answer 352

M = Fd Moment = force x perpendicular distance from pivot Moment unit is Nm

Answer 353

Total clockwise moment = total anti-clockwise moment

Answer 354

to make the anti clockwise and clockwise moments balanced, you should increase the weight/force of the counterweight ‘by increasing the counterweight’s mass of moving it further away from the pivot point both would increase the moment since moment = force x perpendicular distance

Answer 355

Point at which all of mass of an object could be said to act (avg position of mass)

Answer 356

when the line of action of the centre of mass passes beyond the edge of the object’s base

Answer 357

Increasing size of base (Heavy base lowers centre of gravity) Decreasing height Decreases toppling angle

Answer 358

moments about left support as weight moves to right clockwise moment increases perp distance between weight + pivot increases anti-clockwise moment must increase to remain in equilibrium to increase the anti-clockwise moment right upwards force must increase

Answer 359

Can be replenished by natural processes or human activity

Answer 360

Cannot be replenished by natural processes/human activity - only a finite amount

Answer 361

if the forces on an object are balanced, the object will: 1. Continue travelling at a constant velocity 2. Or if stationary -> will remain stationary

Answer 362

Coal oil /gas is burned -> chemical store of coal -> transferred by heating to thermal store of coal oil -> transferred by heating to thermal, kinetic store of water + light and sound radiation Water turned into steam Steam turns turbine -> kinetic store of water -> transferred mechanically to kinetic store of turbine generator -> transferred mechanically to generator Generator generates electricity

Answer 363

Created over a short time span from biomass Fossil fuels were created over hundreds of millions of years -> biofuels are carbon neutral because carbon released when burned is same as carbon used to create them

Answer 364

nuclear reactor is used to turn water into steam nuclear store of uranium -> transferred by heating to thermal store of uranium -> transferred mechanically to kinetic store of turbine -> transferred electrically

Answer 365

kinetic store of air transferred mechanically -> kinetic store of turbine -> transferred electrically to generate electricity

Answer 366

gravitational store of water -> transferred mechanically -> to kinetic store of water -> kinetic store of turbine generator

Answer 367

thermal store of rocks -> transferred by heating -> thermal store of water -> kinetic store of water -> turns to steam which turns turbine

Answer 368

energy from sun transferred by radiation, solar cells transfer energy from sunlight electrically, producing a current + generating electrical power -> electrons flow

Answer 369

light from sun can be used to directly heat water this can be used to heat homes and as a hot water supply

Answer 370

reliable abundant relatively easy to generate electricity non renewable fuel costs greenhouse gases produced acid rain

Answer 371

high energy density no greenhouse gases no acid rain non renewable expensive production of nuclear waste radioactive matter into environment

Answer 372

carbon neutral renewable -reduced fossil fuel reliance labour intensive large amounts of land taken up

Answer 373

no air pollution renewable cheap to run visual pollution expensive to build unreliable

Answer 374

renewable cheap to run no air pollution reliable can be turned on damage to habitats visual pollution can block access to ports trapped vegetation can produce green house gases

Answer 375

no air pollution cheap renewable not efficient -unreliable

Answer 376

heat energy required to raise the temperature of a 1kg mass of a substance by one degree

Answer 377

change in thermal energy = mass x c x change in temperature

Answer 378

Find mass of copper block in kg using balance Place thermometer into smaller bore of copper block and measure initial temp of sample Place copper block into insulating holder and place onto heatproof mat Lubricate electrical heater with petroleum jelly and insert into larger bore in metal block Connect electrical heater to power pack, add ammeter and voltmeter to circuit Switch on power supply, start stopwatch - record values of voltage and current for heating circuit Wait for temp of copper block to rise by between 20 and 30c Switch off power supply, stop stopwatch, record time Wait until temp on thermometer stops rising and record final temp of copper block

Answer 379

if the forces on an object are balanced, the object will: 1. Continue travelling at a constant velocity 2. Or if stationary -> will remain stationary

Answer 380

Water in beaker Find mass Measure initial temp Place electrical heater into beaker of water Add ammeter and voltmeter Start stop clock, switch on power supply Wait for temp to rise between 20 and 30 c Switch off power supply and stop stop clock, record time Wait until temp stops rising and record final temp

Answer 381

A straight line that slopes upwards.

Answer 382

Distance travelled in m ----------------------------------- Time taken in s

Answer 383

if the forces on an object are balanced, the object will: 1. Continue travelling at a constant velocity 2. Or if stationary -> will remain stationary

Answer 384

Speed in a given direction.

Answer 385

Distance in a certain direction.

Answer 386

A physical quantity that has a direction and a magnitude.

Answer 387

A physical quantity that has a magnitude only and not a direction.

Answer 388

Speed Distance Time Mass Energy Power

Answer 389

Force Momentum Weight Gravitational Field Strength

Answer 390

An objects change of velocity per second.

Answer 391

Change in velocity m/s _____________________ Time taken s

Answer 392

Change in velocity m/s _____________________ Time taken s

Answer 393

Acceleration

Answer 394

A horizontal line

Answer 395

Distance travelled.

Answer 396

Draw a triangle under the line. gradient of the line= height of the triangle/ base of the triangle (rise/run)

Answer 397

The height of the triangle under the line/ base of the triangle under the line (acceleration = change of velocity/ time taken) (rise/run)

Answer 398

> Measure out a distance > Station someone at either end. > 1st student gives a signal as the vehicle passes > Second student starts timing. > Stop timing when vehicle passes. > Calculate speed as distance/time

Answer 399

The shape of an object, its state of rest or its motion.

Answer 400

(N) the unit of force. (10N-1kg)

Answer 401

The combined effect of the forces acting on an object.

Answer 402

It either remains stationary or Continues to move at a constant speed.

Answer 403

The movement of an object depends on the size and direction of the resultant force.

Answer 404

Used to find the resultant force of two forces that do not act along the same line.

Answer 405

Mass x Acceleration

Answer 406

If an object is moving at a constant speed, but always changing direction, then it has a velocity rather than a speed.

Answer 407

(sine of opposite angles)

Answer 408

Mass (kg) x Velocity (m/s) unit is kg m/s

Answer 409

It has a size and a direction, so it is a vector

Answer 410

In a closed system, the total momentum before an event is equal to the total momentum after the event.

Answer 411

(Mass of A x Velocity of A) = - (Mass of B x Velocity of B)

Answer 412

…The more the impact force is reduced.

Answer 413

Mass x Change of Velocity (change of momentum) / Time Taken

Answer 414

> Seatbelts (Stop users from continuing forwards when the car stops) Air Bags (Spreads the force of the impact over the upper body, increase impact time) Child Car Seats (Protect children further) Side Bars and Crumple Zones (Increase Impact Time)

Answer 415

Thinking Distance + Braking Distance

Answer 416

Driver’s Reaction Time

Answer 417

Braking Force Action Time

Answer 418

The force of gravity on an object (N)

Answer 419

The quantity of mass of an object (kg)

Answer 420

The force of gravity on an object mass of 1kg (N/kg) The acceleration of free fall

Answer 421

Mass x Gravitational Field Strength

Answer 422

Weight/ Mass

Answer 423

… Its resultant force is its weight.

Answer 424

… the resultant force is its weight - the frictional force on it.

Answer 425

The velocity reached by an object when the drag force is equal and opposite to the force making it move.

Answer 426

Energy transferred by a force.

Answer 427

Force (N) x Distance moved in the direction of force (m)

Answer 428

Energy that heats the objects that rub together and energy that heats the surroundings.

Answer 429

The rate at which energy is transferred per second. Watt

Answer 430

Useful energy transferred (J) / Time taken

Answer 431

Energy of an object due to its position in a gravitational field.

Answer 432

… Its GPE increases

Answer 433

… The weight of an object

Answer 434

Weight (N) x Change of height (m) OR Mass (kg) x GFS (N/kg) x Change in height (m)

Answer 435

1/2 x mass (kg) x speed(2) (m/s(2))

Answer 436

The energy stored in an elastic object when work is done on it.

Answer 437

mass and speed

Answer 438

The energy of a moving object due to its motion.

Answer 439

Measuring cylinder, beaker

Answer 440

Clocks and stopwatches

Answer 441

A micrometre screw gauge

Answer 442

Density = mass/volume

Answer 443

Using displacement

Answer 444

If they have a density of less than of the liquid

Answer 445

Distance moved in a stated direction (change in position)/ change in time

Answer 446

v-u/ change in time

Answer 447

The rate of change of velocity with time

Answer 448

Both magnitude AND direction

Answer 449

Caused by changing of magnitude and direction of velocity By changing in direction of velocity Changing in speed

Answer 450

Speeding up or slowing down

Answer 451

Retardation

Answer 452

Acceleration

Answer 453

Displacement

Answer 454

Uniform acceleration

Answer 455

Non-uniform acceleration

Answer 456

The steeper the gradient the higher the acceleration

Answer 457

The average velocity

Answer 458

Constant velocity

Answer 459

Acceleration

Answer 460

Motion in the positive direction

Answer 461

Motion in the negative direction

Answer 462

A state of rest

Answer 463

Initially his speed is low The air resistance is negligible and he is influenced by his weight only He is speeding up at the rate of gravitational acceleration As the speed increases air resistance increases The acceleration will decrease as resultant force decreases. Until the acceleration becomes zero and the resultant force becomes zero weight=air resistance He has reached terminal velocity

Answer 464

Parachute is opened when there is dynamic equilibrium Air resistance becomes much greater than the force of gravity The net force up while he is moving down He will slow down rapidly and therefore air resistance decreases Resultant force decreases Weight= air resistance - Terminal velocity

Answer 465

The amount of matter inside the object

Answer 466

The force which is caused by gravitation

Answer 467

Mass is constant no matter where it is measured

Answer 468

Varies according to the strength of the gravitational field

Answer 469

A change in motion

Answer 470

A change of shape/ size to an object

Answer 471

The extension is directly proportional to the load beneath the elastic limit

Answer 472

Force = spring constant * Extension F=kx

Answer 473

It goes through the origin and it is a straight line

Answer 474

If you change the shape of the spring or the material that the spring is made out of

Answer 475

It is where the graph stops obeying Hooke’s Law

Answer 476

It can make an object stop, start or change direction

Answer 477

A push or a pull which acts upon an object as a result

Answer 478

Frictional Force Spring force Air resistance Force Tension Force Gravitational force

Answer 479

The force exerted by two surfaces which impedes motion and results in heating

Answer 480

Air resistance

Answer 481

Velocity and Surface Area

Answer 482

Subtraction

Answer 483

Acceleration= zero Resultant force= 0

Answer 484

Acceleration= 0 Resultant force- 0

Answer 485

Resultant force is NOT equal to 0

Answer 486

Centripetal force

Answer 487

It is always changing because of changing direction

Answer 488

If the mass of the object increases If the velocity of the object increases If the radius of the circle decreases

Answer 489

Motion in a circular path due to a perpendicular force

Answer 490

Friction Gravitational Force Tension Normal force

Answer 491

A simple machine that makes work easier to do

Answer 492

Moment= f*d

Answer 493

The total upward force= The total downward force The anticlockwise moment= Clockwise moment

Answer 494

F1 *D1 = F2 * D2

Answer 495

The point where the object’s mass is most concentrated

Answer 496

Suspend the mass from each vertex and trace the plumb lines direction Since the centre of mass will fall below the suspension point the centre of mass will be at the intersection of all the plump lines

Answer 497

Lower centre of gravity Wider base

Answer 498

It has a wide wheel base A low centre of gravity

Answer 499

Reduce the force needed to perform those tasks- they reduce the effort needed to move the load by increasing the distance over which it is acting

Answer 500

A force multiplied by the perpendicular distance from the line of action of the force to the pivot

Answer 501

Only has magnitude

Answer 502

Has magnitude AND direction

Answer 503

Mass, speed and energy

Answer 504

Velocity, acceleration, weight and momentum

Answer 505

Mass * velocity

Answer 506

Kg m/s or Ns

Answer 507

If objects collide the total momentum before the collision is the same as the total momentum after the collision

Answer 508

1. Always decide which direction is positive/negative 2. Always remember that the total momentum before will be the same as the total momentum after

Answer 509

m1u1 + m2u2 = m1v1 + m2v2

Answer 510

Change in momentum

Answer 511

mv - mu OR I= Ft

Answer 512

Ns or kg m/s

Answer 513

It is scalar and is used to maintain the motion

Answer 514

If the work is done by ON the object

Answer 515

If the work is done BY the object

Answer 516

Work done= Force applied * Distance moved

Answer 517

The ability to do work

Answer 518

The energy a material possesses when it is stretched and is put under strain

Answer 519

The energy due to the movement of atoms and molecules in a substance

Answer 520

The energy stored in the bonds of the atoms and molecules

Answer 521

Energy due to the flow of electrons

Answer 522

Energy stored in the nuclei of the atoms

Answer 523

If a body or system has no energy lost or added the total mechanical energy of that body or system remains constant

Answer 524

(KE + PE)f = (KE + PE)i

Answer 525

Increase in PE= Decrease in KE Decrease in PE= Increase in KE

Answer 526

Decrease in PE= increase in KE + Energy lost Decrease in KE= Increase in PE + Energy lost

Answer 527

Decrease in PE= Increase in KE- Energy added Decrease in KE= increase in PE- Energy added

Answer 528

Energy transferred/ time taken P=E/t OR work done/ time

Answer 529

Energy cannot be created nor destroyed it can only change from one form to another

Answer 530

Useful energy output/energy input *100%

Answer 531

The heat from the fuel boils water to make steam It expands and pushes against the blades of a turbine The spinning turbine then turns the generator

Answer 532

Furnace–> Boiler–> turbine–> generator

Answer 533

Some is ALWAYS dissipated into the surrounding/ lost to the surroundings

Answer 534

chemical energy stored in fuel – water, including the energy stored in waves, in tides, and in water behind hydroelectric dams – geothermal resources – nuclear fission – heat and light from the Sun (solar cells and panels) – wind

Answer 535

Wave, tides, hydroelectric, geothermal, solar cells/panels and wind

Answer 536

Nuclear, tidal and geothermal

Answer 537

Nuclear fusion

Answer 538

Pascals Pa

Answer 539

P= Force/ Area

Answer 540

By reducing the area

Answer 541

By increasing the area

Answer 542

Pressure acts in all directions Pressure increases with depth Pressure depends in the density of the liquid Pressure does not depend on the shape of the container

Answer 543

Pressure= Density * Gravitational Potential * Height

Answer 544

It becomes less because there is less weight above

Answer 545

Mercury is the densest liquid and therefore it has the shortest height of liquid compared with other liquids

Answer 546

Pressure of gas= Pressure of liquid+ Pressure of atmosphere

Answer 547

Around the time of the Great Plague in the 1660s

Answer 548

Balanced forces mean no change in velocity

Answer 549

The forces must be balanced

Answer 550

Zero resultant force

Answer 551

If there is an unbalanced force, then the object will accelerate in that direction

Answer 552

Acceleration

Answer 553

Starting Stopping Speeding up Slowing down Changing direction

Answer 554

The greater the acceleration or deceleration

Answer 555

The smaller the acceleration

Answer 556

You need a bigger force

Answer 557

The resultant force - produces acceleration

Answer 558

If object A exerts a force on object B then object B exerts the exact opposite force on object A

Answer 559

When skater A pushes on B, she feels an equal and opposite force from skater B. Both skaters feel the same sized force in opposite directions and accelerate away from each other. However skater A will be accelerate more than B as she has smaller mass (f = ma)

Answer 560

You push back against the water with your arms and legs, and the water pushes you forwards with an equal-sized force in the opposite direction

Answer 561

Using a toy car on a ramp

Answer 562

1) Using two light gates and a ramp, mark a start point in the ramp - same point each time 2) Measure the distance between the two light gates 3) Let the car go from top of ramp 4) The light gates are connected to a computer. When the car passes a beam of light is broken and a time is recorded 5) Repeat experiment for average time 6) Use these times and the distances recorded to find the average speed

Answer 563

1) Mass - load objects onto car 2) Friction - use different materials for the ramp 3) Acceleration - changing starting point on the ramp (higher/lower) 4) Speed - change the angle of the ramp 5) Size and shape - use different cars

Answer 564

How fast an object is going m/s

Answer 565

Velocity shows how fast your going as well as the direction it is going in

Answer 566

How quickly velocity changes

Answer 567

Change in speed or change in direction

Answer 568

Average speed = distance/time

Answer 569

Acceleration = Change in velocity/ time taken m/s2 (squared)

Answer 570

Speed - the steeper the diagonal line, the faster it is going

Answer 571

Where it has stopped

Answer 572

Acceleration or deceleration

Answer 573

Its speeding up (increasing gradient)

Answer 574

Its slowing down (decreasing gradient)

Answer 575

Going back to the starting point

Answer 576

Acceleration

Answer 577

A steady speed

Answer 578

The greater the acceleration/ deceleration

Answer 579

Acceleration

Answer 580

Deceleration

Answer 581

Changing acceleration

Answer 582

Yes - the are under any section of the graph is equal to the distance travelled in that time taken

Answer 583

(v-u)/a x t

Answer 584

When an object is falling with no driving force (other than gravity) acting on it

Answer 585

A fluid eg air as it will eventually reach terminal velocity

Answer 586

1) Bigger force accelerating them than resistance 2) As velocity increases, resistance increases 3) Gradually acceleration is reduced 4) Resistance force = accelerating force - cant accelerate anymore 5) It has reached maximum velocity (terminal velocity)

Answer 587

Their size and area

Answer 588

Gravity and because of air resistance

Answer 589

On the moon because their is no air, hamsters and feathers were dropped simultaneously and hit the ground together. On earth air resistance causes things to fall at different speeds and terminal velocity is determined by its drag compared to weight. Drag depends on its shape and area

Answer 590

A human skydiver - without the parachute open he has a small area and force equal to his weight pulling him down. He reaches a terminal velocity of 120 mph. However with the parachute open theres more air resistance and still the same force pulling him down meaning that his terminal velocity goes down to 15 mph which is much safer for landing

Answer 591

Sycamore seeds because they have a small weight and a large surface area so will reach terminal velocity really quickly and will fall slowly

Answer 592

Seeds of different sizes - mass and wing length should be measured. Use seeds with similar mass but different wing lengths

Answer 593

Drop each one from similar heights and time how long it takes for one to hit the floor (The higher you drop them from the better) Repeat the experiment the experiment for each seeds and find the average

Answer 594

Plot a graph of the length of wings against time taken to hit the ground

Answer 595

Yes - bigger wings means bigger surface area so higher drag. Higher drag means lower terminal velocity and so slower free fall (graph should show a diagonal straight line going up)

Answer 596

The force of attraction between all masses

Answer 597

It makes all objects accelerate towards the ground on the surface of the planet It gives everything weight It keeps planets, moons and satellites in their orbit

Answer 598

The balance between the forward motion of the object and the force of gravity pulling it inwards

Answer 599

The amount of “stuff” in an object

Answer 600

The pull of gravity on every object (towards the centre of the earth)

Answer 601

It will have the same mass on the earth and moon but different weight

Answer 602

The forces of gravity pulling on the moon are less

Answer 603

Newtons (N)

Answer 604

Kilograms (kg)

Answer 605

The equation: Weight = mass x gravitational field strength W = m x g

Answer 606

Earth - 10 N/kg Moon - 1.6 N/kg

Answer 607

A push or a pull

Answer 608

Straight downwards

Answer 609

Between two charged objects - direction depends on type of charge

Answer 610

When something is speeding up

Answer 611

Slow down objects

Answer 612

Due to an aeroplane wing

Answer 613

Due to a rope or cable

Answer 614

- Reaction = gravity - Thrust = Drag

Answer 615

Motion - if an object has no force moving it, friction always slows it down

Answer 616

A driving force

Answer 617

Friction between solid surfaces which are gripping Friction between solid surfaces sliding last each other Resistance from fluids (liquids or gases)

Answer 618

Put lubricants like oil or grease between the two surfaces to prevent the wear of the two surfaces in contact

Answer 619

Keep objects streamlined like sports cars or put deflectors on them like what lorries and caravans have

Answer 620

Roof boxes

Answer 621

The lower the top speed of a car - opposite to this is s parachute

Answer 622

The size of all the different forces and their direction

Answer 623

A vector quantity

Answer 624

Size and direction

Answer 625

Force Velocity Displacement Acceleration Momentum (mostly physical quantities)

Answer 626

Mass Temperature Time Length

Answer 627

Combine vectors - work along the same line

Answer 628

The distance covered in the time between the driver first spotting a hazard and the car coming to a complete stop

Answer 629

The thinking and braking distance

Answer 630

The distance the car travels between the driver noticing the hazard and applying the breaks

Answer 631

1) How fast you’re going 2) How tired you are - tiredness, drugs, alcohol and old age can affect your reaction time

Answer 632

The distance the car travels during deceleration whilst the breaks are being applied

Answer 633

1) How fast your going - the faster your going, the further it takes to stop 2) The mass of the vehicle - the larger the mass, the longer it takes to stop 3) How good your brakes are - should be checked regularly 4) How good the grip is - depends on road surface, weather conditions and tyres “aquaplaning”

Answer 634

Lashing rain, thick fog and bright upcoming lights might mean that the driver doesn’t notice a hazard until they’re quite close having a shorter distance available to stop in

Answer 635

A vector quantity

Answer 636

Momentum (kg m/s) = Mass(kg) x Velocity(m/s)

Answer 637

The more momentum

Answer 638

Momentum after

Answer 639

Momentum is conserved when no external forces act f

Answer 640

Positive and negative

Answer 641

Changes in momentum

Answer 642

Force (N) = Change in momentum(kg m/s) /time taken(s)

Answer 643

In a car crash - the forces on the body are very large and are more likely to cause injury

Answer 644

The longer it takes for a change in momentum, the smaller the force and so the less serve the injuries will be

Answer 645

Increases time taken for the car to stop

Answer 646

They stretch slightly increasing the time taken for the wearer to stop. This reduces the forces acting on the chest h

Answer 647

Slow you down gradually

Answer 648

The turning effect of a force

Answer 649

Moment(Nm) = Force(N) x perpendicular distance (m) (between line of action and pivot)

Answer 650

The force on the spanner causes a turning effect or moment on the nut. A larger force would mean a larger moment

Answer 651

Exerts a larger moment because the distance from the pivot is greater

Answer 652

Push at right angles to the spanner

Answer 653

It means a smaller moment because the perpendicular distance between the line of action and the pivot is smaller

Answer 654

The point of suspension

Answer 655

The point at which the weight of the body acts

Answer 656

When it is vertically below the point of suspension - no moment as the pivot is in line with the line of action of the force

Answer 657

1) Suspend the shape and a plumb line from the same point and wait to until they stop moving 2) Draw a line along the plumb line 3) Do the same again but suspend shade from different pivot point 4) The centre of gravity is where the two lines meet

Answer 658

Look at the lines of symmetry (where two lines cross in the middle is the c.og)

Answer 659

Total anticlockwise moments = Total clockwise moments When acting in a balanced object

Answer 660

Its centre of mass is on the pivot, so it does have a turning effect

Answer 661

No - if a heavy object is placed on the rod, the support closest to the object will provide a larger force

Answer 662

A resultant moment - so the object will turn!

Answer 663

Extension is proportional to force

Answer 664

Natural length

Answer 665

It stretches - the weight pulls down with force F, is producing an equal and opposite force at the support Also happens in helical springs

Answer 666

That the extension of a stretched wire is propotional to the load or force

Answer 667

If a pair of opposite forces are applied to each end

Answer 668

Use a spring

Answer 669

A clamp Spring A hanging mass Weighted stand Extra masses

Answer 670

1) Measure length of spring without any load (natural length) 2) Add one mass at a time allowing the spring to come to a rest, then measure new length of spring -record results 3) The extension is the change in length from the original length 4) Repeat this process and calculate an average

Answer 671

When the force is great enough

Answer 672

A straight line relationship between force and extension

Answer 673

The graph starts to curve - it is called the elastic limit

Answer 674

It stretches - the weight pulls down with force F, is producing an equal and opposite force at the support Also happens in helical springs

Answer 675

That the extension of a stretched wire is propotional to the load or force

Answer 676

If a pair of opposite forces are applied to each end

Answer 677

Use a spring

Answer 678

A clamp Spring A hanging mass Weighted stand Extra masses

Answer 679

1) Measure length of spring without any load (natural length) 2) Add one mass at a time allowing the spring to come to a rest, then measure new length of spring -record results 3) The extension is the change in length from the original length 4) Repeat this process and calculate an average

Answer 680

When the force is great enough

Answer 681

A straight line relationship between force and extension

Answer 682

The graph starts to curve - it is called the elastic limit

Answer 683

a = F/ma = 600/60a = 10ms-2

Answer 684

Speed = Distance/Time

Answer 685

Force = Mass x Acceleration = 400 kg x 0.5m/s^2 = 200N

Answer 686

a = v - u / t a = f/m = force (in N) / mass (in Kg)

Answer 687

W = mgW = 3500 x 10= 35000 N

Answer 688

m = W/gm = 250/10m = 25kg

Answer 689

W = mgW = 550 x 10= 5500 N

Answer 690

m = W/gm = 720/10m = 72kg

Answer 691

F = ma = 800 x 5F =4000N

Answer 692

m = F/am = 50000/1.5m = 33333kg

Answer 693

p = mvv = p/mv = 20000/1500p = 13.33 m/s

Answer 694

p = mvm = p/vm = 16000/25m = 640kg

Answer 695

p = mvp = 500 x 30p = 15000 kgms-1

Answer 696

moment = force x distance of force from pivot or moment = F x d Moment in Nm Force in N Distance in M

Answer 697

picture 1 - downward force (weight) is greater than upward force (air resistance)- sky diver is accelerating picture 2 - air resistance is increasing so sky diver is accelerating more slowly picture 3 - sky diver has reached terminal velocity

Answer 698

A moment The moment of a force about a fixed point or axis is the turning effect of the force about that point and is measured by the product of the force and the perpendicular distance from the point to the line of action of the force.

Answer 699

moment = 200 x 2.5 = 500 Nm

Answer 700

moment = 400 x 3.5 = 1400 Nm

Answer 701

Total momentum before collision = 46 000 kg m/sTotal momentum after collision = 46 000 kg m/sMomentum = mvv=momentum/mv=46 000/1800v=25.55 m/s

Answer 702

p_locomotive_initial = 560000 kg m/s p_carriage_initial = -120000 kg m/s p_total_initial = 560000 kg m/s - 120000 kg m/s p_total_initial = 440000 kg m/s p_carriage_final = 8000 kg × 10 m/s 440000 kg m/s = p_locomotive_final + 80000 kg m/s p_locomotive_final = 360000 kg m/s velocity_locomotive_final = 360000 kg m/s / 20000 kg velocity_locomotive_final = 18 m/s

Answer 703

a=f/m=2500/500=5 m/s^2

Answer 704

a=v-u/t=25-10/3=5m/s^2

Answer 705

Similarity - they both have magniture Difference - A vector also has direction

Answer 706

scalar - e.g. 60 seconds

Answer 707

momentum = mass x velocity

Answer 708

10000 Kg m/s

Answer 709

p = 13.33ms-1

Answer 710

force = change in momentum / time taken force = mv - mu /t or change in momentum = force x time taken

Answer 711

Seat belts Airbags Crumple Zones

Answer 712

Change in momentum= time taken x force The seat belt increases the time of impact which reduces the forces on the body as momentum changes to zero. The seat belt stretches which increases the area over which the force acts reducing the pressure on the body.

Answer 713

change in momentum=time x force Air bags increase the time taken for the head’s momentum to reach zero, so reduce the forces on it. They act a soft cushion and prevent cuts.

Answer 714

change in momentum = time x force Crumple Zones increase the time it takes for the car to stop. Increasing the time reduces the forces impacting the car and the forces on the passengers inside the car.

Answer 715

It reduces to zero in a very short amount of time and therefore exerts a high amount of force on the car.

Answer 716

Race cars are faster than ordinary cars and therefore the forces on the body would be greater in a crash. The seat belts have a greater surface area and this reduces the pressure on the body.

Answer 717

ρ = m/Vρ = 90/10ρ = 0.09kg / 0.00001m3ρ = 9000 kg/m3

Answer 718

ρ = m/VV = m/ρV = 4/2700V = 0.00148 m3

Answer 719

1000000 cm3.

Answer 720

density = mass/volume

Answer 721

g/cm³ or kg/m³

Answer 722

measuring cylinder

Answer 723

electronic balance or electronic scales

Answer 724

1. Set it to zero first 2. Place on a flat level surface

Answer 725

1. Place eyes level with the water. 2. Place on a flat surface 3. Use a clean cylinder

Answer 726

1. The temperature of water should be kept constant as hot water is less dense. 2. The water should be of the same type, for example water with salt in it could be more dense.

Answer 727

The weight is spread over a larger area. This means that there is less force per unit area acting on the surface and therefore the surface can support the object better.

Answer 728

The weight is spread over a small area. This means that there is a lot of force per unit area acting on the surface and therefore the floor will get damaged.

Answer 729

pressure = force /area P - pressure in pascals (Pa) F - force in newtons (N) A - area in m2

Answer 730

pressure = density x g x depth P = ρgh

Answer 731

For the top: P = 1000 x 10 x 3= 30000Pa For the bottom:P = 1000 x 10 x 7= 70000Pa The difference is therefore 70000 - 30000 = 40000 Pa

Answer 732

P = ρgh P = 1000 x 10 x 6 = 60000Pa The density of water is 1000

Answer 733

Energy is lost to heat the copper that the tank is made from and to the atmosphere.

Answer 734

Energy is used to overcome the various friction forces that oppose motion. This can also cause energy to be transferred to heat. Lost as sound (engine noise) Lots of energy is converted to heat which is lost or heats the surroundings

Answer 735

Energy is not created or destroyed in any process. Only transferred from one form to another.

Answer 736

useful output/total input x 100%

Answer 737

whenever a current flows

Answer 738

from the sun, luminous objects, light bulbs

Answer 739

loudspeakers etc

Answer 740

anything that possesses motion

Answer 741

Energy stored in the nuclei of atoms

Answer 742

Energy due to the movement of atoms and molecules in a substance

Answer 743

Energy of an object due to its position in a gravitational field.

Answer 744

Energy a material possesses when it is stretched and is put under strain

Answer 745

possessed by foods, fuels, batteries

Answer 746

Forms of stored energy

Answer 747

wastes less energy

Answer 748

It is always dissipated as heat

Answer 749

sound - electrical - sound

Answer 750

electrical - light and sound

Answer 751

chemical - electric - kinetic, sound, heat, light

Answer 752

electrical to chemical

Answer 753

kinetic energy

Answer 754

It will have thick arrow for the useful energy output

Answer 755

Most energy is wasted as heat; only small % is useful output

Answer 756

transfer of heat energy by electromagnetic waves

Answer 757

The transfer of energy by particles

Answer 758

fluids (liquids and gases)

Answer 759

all objects

Answer 760

the bigger the temperature difference

Answer 761

emitting and absorbing heat radiation

Answer 762

It will absorb more radiation than it emits

Answer 763

Emit more radiation than it absorbs

Answer 764

Vibrating particles which have gained more KE pass this gain in KE to neighbouring particles

Answer 765

The process of particles sharing their KE is passed on throughout the solid causing rise in temp at the other side of the solid. This rise in temp means that the object now loses more heat from its surface as a means of cooling down again.

Answer 766

IR radiation

Answer 767

When more energetic particles move from the hotter region to the cooler region and take their heat energy with them.

Answer 768

Heat energy transferred from heater coils to water via conduction. Particles near coils get more energy and move faster and because there is more distance between the particles, the water expands and becomes less dense. Hotter, less dense water rises above the denser, cooler water and displaces it out of the way in doing so making it sink to the heater coils Process repeats with convection currents and all water will be heated

Answer 769

In roundish/squarish containers because they allow the convection currents to work best

Answer 770

Because any hot water rises due to its low density - it wouldn’t sink down to displace cooler water!

Answer 771

Thick layer of fibreglass wool laid out across loft floor and ceiling reduces heat loss from CONDUCTION AND CONVECTION

Answer 772

Strips of foam/plastic around doors and windows to stop heat loss via CONVECTION

Answer 773

Lagging such a fibreglass wool reduced conduction and radiation

Answer 774

Two layers of glass for insulation with an air cavity to reduce CONDUCTION AND CONVECTION

Answer 775

Reduce by stopping radiation and conduction

Answer 776

Foam squirted into the gap between inner and outer bricks stop CONVECTION AND RADIATION by being lined with shiny foil to reflected the heat back in. Insulating foam and trapped air pockets in it (air is an insulator) reduce CONVECTION

Answer 777

Clothes - trap air near skin to reduce convection and conduction because air is not a solid Hair stands on end to trap a thicker layer of insulating air around the body - reduce CONVECTION Clothes also reduce radiation as the material absorbs some of the heat radiated out by our bodies

Answer 778

energy is transferred and work is done

Answer 779

when energy is transferred

Answer 780

most energy is transformed into heat and some sound This is “wasted” energy

Answer 781

work = force x distance

Answer 782

the rate of doing work i.e. how much energy is transferred / second

Answer 783

one that transfers a lot of energy in a short space of time

Answer 784

mass velocity

Answer 785

the energy stored in an object of mass m when you raise it to height h against gravity g

Answer 786

The GPE lost

Answer 787

coal oil gas nuclear

Answer 788

fuel (chemical) steam (heat energy) turns a turbine (kinetic) drives a generator (kinetic) makes electricity (electrical)

Answer 789

Releases lots of energy relatively cheaply Energy from fossil fuels not reliant on the weather - RELIABLE We have lots of fossil fuel plants already so no money needs to be spent on new technology to use them

Answer 790

release CO2 into atmosphere when burned - global warming and climate change burning coal and oil release S02 which causes acid rain; this damages tree, buiding and life NON-RENEWABLE

Answer 791

Nuclear fission of uranium produces heat to make steam to drive turbines rather than burning. NUCLEAR - HEAT - KINETIC - ELECTRICAL

Answer 792

reactors are expensive to build and maintain - longer to start up than fossil fuel ones processing of uranium before use causes pollution risk of radioactive material leak radioactive waste expensive to decommission when they are old and inefficient

Answer 793

no greenhouse gases - NO GLOBAL WARMING still plenty of uranium fuel reserves

Answer 794

Put up lots of wind turbines in exposed places. Wind turbines convert kinetic energy of moving air to electrical energy. WIND TURNS BLADES WHICH TURN A GENERATOR INSIDE

Answer 795

cheap to run tough and reliable free no polluting waste and RENEWABLE

Answer 796

spoil the view noisy wind not always strong enough to generator power when demand increases UNRELIABLE Expensive to set up farms - especially out at sea

Answer 797

Hot rocks lie under ground Water is pumped under ground and forced back up to pressure to turn a turbine and generator HEAT - KINETIC - ELECTRICAL

Answer 798

heat building directly

Answer 799

slow decay of radioactive materials like uranium deep inside the Earth

Answer 800

free renewable no real environmental issues

Answer 801

cost of drilling down cost of building a plant is greater than the energy given out few places where this is an economic option

Answer 802

transform light energy from the Sun directly into electrical energy generate direct current

Answer 803

renewable energy source expensive initially but after energy from sun is free and no running costs really no pollution good in remote places where there is not much choice and satellites good to power calculators and watches CAN BE CONNECTED TO RECHARGEABLE BATTERIES TO CREATE A SYSTEM THAT CAN STORE ENERGY DURING THE DAY FOR USE AT NIGHT

Answer 804

very expensive initially used to generate electricity on a small scale not practical and too expensive to connect to the National Grid - cost of doing so is more than achieved from the electricity generated unreliable - NO SUN AT NIGHT

Answer 805

Black water pipes in a glass box. Glass traps heat and light that is absorbed by the black pipes and heats water.

Answer 806

Expensive to set up renewable and free after time good for small scale production

Answer 807

Curved mirror directs Sun’s heat and light on a pan. Renewable energy source for outdoor cooking but slow, bulky and unreliable and needs strong sunlight to work!

Answer 808

small wave converters take the up and down motion of waves and use it to drive a generator. KINETIC - ELECTRICAL

Answer 809

no pollution renewable no fuel costs minimal running costs useful for small scale production on small islands

Answer 810

spoil view hazard to boats UNRELIABLE - waves stop when wide and tide affected high initial costs

Answer 811

Tidal barrages are big dams built over estuaries with turbines in them. Tide comes in and fills up estuary - driving turbines as it comes in Water is then let out through turbines at a controlled speed and drives turbines KINETIC - ELECTRICAL

Answer 812

no pollution renewable predictable although not up to demand!! no fuel cost minimal running cost

Answer 813

prevents free access by boats spoils view alters habitat for wildlife height of tide is variable - low tide = LESS ENERGY high initial costs

Answer 814

Requires flooding of valley by building a dam Rainwater caught and allowed through turbines converting GPE of water to KE as it falls. This is converted to Electrical energy by a generator

Answer 815

renewable no pollution no fuel and running costs immediate response to INCREASED DEMAND NO RELIABILITY ISSUES EXCEPT IN DROUGHT

Answer 816

BIG Impact on the environment due to flooding the valley (rotting vegetation releases methane and CO2) loss of habitat for some species reservoirs unsightly high initial costs

Answer 817

Spare electricity is used to pump water up to a higher reservoir This can be released quickly during peak demand to supplement the steady delivery from big power stations

Answer 818

large power stations have boilers that are left running all night leading to surplus electricity build up

Answer 819

HEP generates power Pumped storage is a way of storing energy which has already been generated

Answer 820

converts kinetic energy of moving bicycle wheel into electrical energy. Lamp converts electrical energy to heat and light

Answer 821

heat and sound

Answer 822

1. Block of ice put into test tube under gauze so it doesn’t rise again and water at top is heated. Ice not melted because conduction doesn’t occur efficiently in fluids 2. Hold match away from flame. Only light when very near to flame; air is a poor conductor of heat. 3. cylinder of brass fitted onto some wood and paper around middle. Paper is heated over flame. Paper doesn’t brown on brass side as metal conducts heat away from the paper. Paper scorched on wooden side as wood is a bad conductor (heat just builds up under paper and scorches it)

Answer 823

they collide and share their KE

Answer 824

because convection requires particles that can move about and create convection currents

Answer 825

A lit candle is placed in a mine with 2 chimneys. As the flame burns , air around it heats up, expands and becomes less dense. This heated air rises up out of the mine through one chimney. Low pressure in mine so fresh air rushed in to replace the lost air.

Answer 826

metal pan conducts heat from the flame which heats water particles. Heated water rises because it is less dense and so cooler air replaces the water that rose

Answer 827

the transfer of heat energy by IR waves and does not involve particles.

Answer 828

SA difference in temp between object and surroundings texture of surface colour

Answer 829

shiny, white

Answer 830

matt black

Answer 831

Black is better at absorbing than white. Shiny is better at reflecting than matt

Answer 832

PLASTIC STOPPER doesn’t conduct heat (insulator) prevent convection from taking place VACUUM - no particles so no convection or conduction THIN SILVERED WALLS -reduce radiation by reflected heat back into flask

Answer 833

Air trapped in fibred prevents CONVECTION

Answer 834

Savings - initial cost

Answer 835

initial cost/annual saving

Answer 836

one that is not replaced at the same rate as it is used

Answer 837

insulating effect of certain gases in Earth’s atmosphere. They allow short-wavelength IR from Sun into Earth’s atmosphere but absorb the re-emitted long-wavelength IR. This is trapped and heats the Earth.

Answer 838

They all have carbon in them and when burnt, release CO2. Damaging effect on environment

Answer 839

There is enough to meet our energy requirements and with ‘breeder’ nuclear reactors to generate more nuclear fuel, meet demand indefinitely.

Answer 840

gas - quite quick response coal - longer to respond as takes longer to fire up nuclear - only suited to steady supply as the reactors cannot be quickly run up to operating temp or closed down HEP - very quick

Answer 841

microphone

Answer 842

every result is wrong by the same amount

Answer 843

do same thing, repeat it but get different results

Answer 844

instrument is not set to zero

Answer 845

the fraction of energy supplied to a device which is transferred into a useful form

Answer 846

1/2mv2 = mgh (cancel m) so 0.5 x (20)2 = 10 x h so h = 20m

Answer 847

it has stopped

Answer 848

acceleration

Answer 849

g/kg etc. measured using a mass balance/scales

Answer 850

Newtons (N) using a spring balance or a newton meter

Answer 851

acts straight upwards, counter-acting the force of gravity/weight

Answer 852

by putting a lubricant eg. oil/grease between the surfaces.

Answer 853

streamlining the object

Answer 854

it increases

Answer 855

Mass friction- is the surface a rug or a wooden plank? acceleration due to gravity- higher/lower up the ramp angle of ramp

Answer 856

accelerating force and resistance.

Answer 857

shape and area

Answer 858

increased drag

Answer 859

smaller acceleration

Answer 860

any from force/velocity/displacement/acceleration/momentum

Answer 861

by combining vectors

Answer 862

thinking distance and braking distance

Answer 863

Speed and how dopey you are e.g tiredness, drugs, alcohol, old age, inexperience

Answer 864

Speed, mass of vehicle, how good the brakes are, how good the grip is eg. road surface/weather/tyres

Answer 865

The point on an object at which its mass may be thought to be concentrated.

Answer 866

Where its axis of symmetry cross.

Answer 867

Suspend the material from a stand. Use a ‘plumbline’ to draw a vertical line from the rod downwards. Repeat this process from a second point- the centre of mass will be where the two lines cross.

Answer 868

Motion of any object that moves to and fro along the same line.

Answer 869

A pendulum made up of a small spherical bob suspended by a string from a fixed point.

Answer 870

The distance an object moves from its equilibrium position to its higher position on either side.

Answer 871

… the number of complete cycles of oscillation per second. (measured in Hz)

Answer 872

1/ Frequency of the oscillations (Hz)

Answer 873

The turning effect of a force.

Answer 874

Force (n) x Perpendicular distance from the line of action of the force to the pivot (m)

Answer 875

Load Effort Pivot Fulcrum

Answer 876

A lever used so that a weight or force can be moved by a smaller force than it could previously.

Answer 877

The line along which a force acts.

Answer 878

The sum of all the clockwise moments around a point The sum of all the anticlockwise moments around a point

Answer 879

When its line of action remains within its base.

Answer 880

When its line of action strays from inside the base.

Answer 881

By widening the base

Answer 882

The difference between the sum of the clockwise moments and the sum of the anticlockwise moments about the same point if they are not equal.

Answer 883

If the resultant moment around an object’s turning point is not 0.

Answer 884

The acceleration of an object moving around in a circle towards the centre of the circle.

Answer 885

The resultant force towards the centre of a circle acting on an object moving in a circular path. This is what causes the centripetal acceleration.3

Answer 886

The velocity is constantly changing because the objects direction is always changing.

Answer 887

> Mass Speed Radius of the Circle

Answer 888

Force/ Area

Answer 889

… acts equally in all directions.

Answer 890

is transmitted to other parts of the liquid because it is virtually incompressible.

Answer 891

It uses the pressure in a liquid to enter a force.

Answer 892

A force multiplier.

Answer 893

Anything moving along a curved path.

Answer 894

Whatever is preventing an object from flying off of its circular course. eg. tension in a rope, gravity of the sun, friction between tyres and the road.

Answer 895

Velocity = circumference/time period.

Answer 896

It has a larger surface area. P1=P2 F1/A2=F2/A2

Answer 897

PE = mgh PE = 70 x 10 x 8 = 5600 J

Answer 898

PE = mgh PE = 70 x 10 x 8 = 5600 J

Answer 899

PE = mgh m = PE/gh m = 90000 / 10 x 6 m = 90000 / 60 = 1500kg

Answer 900

PE = mgh PE = 70 x 10 x 6 = 4200 J

Answer 901

PE = mghm = PE/ghm = 150000 / 10 x 8m = 150000 / 80= 1875 kg

Answer 902

WD = F x d WD = 80 x 6 = 480 J

Answer 903

WD = F x d d = WD/F d = 200000 / 3000 = 66.67 m

Answer 904

WD = F x d WD = 70 x 12 = 840 J

Answer 905

WD = F x d d = WD/F d = 1000000 / 5000 = 200 m

Answer 906

efficiency = useful energy output / total energy input

Answer 907

efficiency = useful energy output / total energy input efficiency = 2.5 / 11 x 100 = 0.227 x 100 = 22.7% efficient

Answer 908

efficiency = useful energy output / total energy input efficiency = 3700 / 4000 x 100 = 0.925 x 100 = 92.5% efficient

Answer 909

To show the input and ouput energy in a system and show the efficiency of energy transfer.

Answer 910

It is generated from another energy source such as fossil fuels or nuclear power.

Answer 911

Conduction Convection Radiation

Answer 912

Power = work done/ time taken Work done = Power x time taken 1200 x 15 x 60 = 1080000J

Answer 913

PE = mgh 30=0.16x 10 x h h = 30/0.16 x 10 18.75m

Answer 914

Energy cannot be created or destroyed.

Answer 915

Fuel is burned to produce heat2.Water is heated to produce steam - which drives the turbines.3. The turbines power the generators which produce electricity.

Answer 916

Kinetic, gravitational potential, elastic potential, nuclear, chemical, heat (thermal), sound, light, electrical

Answer 917

The transfer of thermal energy through a substance without the substance itself moving; caused by the spreading vibration of particles in the substance

Answer 918

The transfer of thermal energy through a fluid by the rising of less dense, hotter fluid, and falling of the denser, cooler fluid.

Answer 919

The transfer of heat by infra red radiation

Answer 920

Transfer of energy

Answer 921

KE = 1/2mv^2

Answer 922

KE at bottom

Answer 923

energy transfer (work done)

Answer 924

The kinetic energy from the wind spins the turbines, which drive generators which convert the kinetic energy into electrical energy

Answer 925

heat energy -> kinetic energy -> electrical energy

Answer 926

heat -> electrical

Answer 927

light -> electrical

Answer 928

chemical energy -> heat energy -> kinetic energy -> electrical energy

Answer 929

nuclear energy -> heat energy -> kinetic energy -> electrical energy

Answer 930

Equally in all directions

Answer 931

ΔP = ρgh

Answer 932

N/kg or m/s^2

Answer 933

speed = distance/time

Answer 934

Area under the curve

Answer 935

change in velocity over time (acceleration); change in shape

Answer 936

A force which opposes motion

Answer 937

The object initially accelerates toward the Earth due to the gravitational force. As the object’s velocity increases, so too does its air resistance. Eventually, the force of air resistance = gravitational force, so the forces will be balanced. According to Newton’s 1st Law, unless acted on by a force, an object will travel at constant velocity

Answer 938

s.d. = thinking distance + braking distance

Answer 939

Metal condition of driver; tiredness; influence of drugs; alcohol; medication; level of concentration

Answer 940

speed; road conditions; tyre conditions; car mass; brake conditions

Answer 941

the point within something at which gravity can be considered to act

Answer 942

Moment = Force x Perpendicular distance

Answer 943

The extension of an elastic material is proportional to the force applied until the material reaches its elastic limit

Answer 944

A material which will retain its original shape after a force which has been deforming it has been removed

Answer 945

the net force acting on an object

Answer 946

The resultant force of an object is proportional to the acceleration.

Answer 947

Where weight forces of an object are balanced with air resistance, causing the object to move at a constant speed.

Answer 948

To obey Hooke’s law, the force must be proportional to the extension.

Answer 949

The difference between the new and original length of an object

Answer 950

kinetic, gravitational, chemical, electrostatic, magnetic, thermal, nuclear, elastic

Answer 951

by heating, by radiation, mechanically, electrically

Answer 952

useful energy out/total energy in

Answer 953

The energy stores in an object if it is raised above the ground.

Answer 954

mass x height x g

Answer 955

The energy stored in an object when it is moving at a constant speed.

Answer 956

0.5 x mass x velocity ^2

Answer 957

the mechanical energy transfer

Answer 958

force x distance

Answer 959

the rate of doing work

1. Motion, Forces and Energy Flashcards

(1086 cards)