1. Motion, Forces and Energy Flashcards

Question

Spring constant

Answer 1

Spring constant (N/m) = Force (N)/Extension (m)

Answer 2

The limit for Hooke's law applied to the extension of a stretched spring

Answer 3

Force (N) * Perpendicular distance to pivot (m)

Answer 4

A body is in equilibrium if there are no net forces and no net moments. (balanced)

Answer 5

The imaginery point within an object that the mass and weight of the object is evenly dispersed around (also known as the centre of mass).

Answer 6

If a shape can be reflected about any line without changing the shape, the object has 'line symmetry' and the line used is called the line of symmetry.

Answer 7

The product of the mass and velocity of an object. The units are kg m/s. (The oomph of an object)

Answer 8

p = mv p - momentum (kgm/s) m - mass (kg) v - velocity (m/s)

Answer 9

The natural law that the total momentum of a system of objects after a collision is the same as the total momentum before the collision, as long as there are no external forces acting on the system.

Answer 10

READ KOGNITY ELSA AND DONT BE LAZY

Answer 11

READ KOGNITY ELSA AND DONT BE LAZY

Answer 12

The change in momentum of a body, usually caused by a collision or impact.

Answer 13

ΔP = FΔt ΔP = Impulse (kgm/s) F = Force (N) Δt = Change in time (s) ΔP = mv - mu Impulse = final momentum - initial momentum Impulse = change in momentum (Both formulas work and can be used) Ft = mv - mu

Answer 14

In an isolated system the total energy remains constant. Energy cannot be created or destroyed, only converted from one store to another.

Answer 15

Energy is moved from one store to another when work is done.

Answer 16

The energy stored in an object lifted upwards in a gravitational field.

Answer 17

Energy stored in a moving object.

Answer 18

The energy stored in an object lifted upwards in a gravitational field.

Answer 19

Kinetic Gravitational Potential Chemical Potential Elastic Potential Nuclear Electrostatic Thermal (internal kinetic)

Answer 20

Mechanical (Forces) Electrical Heating Electromagnetic (Sound or other waves eg light.)

Answer 21

Ek = 1/2mv² Ek = Kinetic Energy ( J ) m = mass (kg) v = speed (m/s)

Answer 22

Ep = mgΔh Ep= Gravitational Potential ( J ) m = mass ( kg ) Δh = change in height (m)

Answer 23

Work done is the energy transferred to an object when a force moves the object over a distance.

Answer 24

W = Fd W = Work ( J ) F = Force (N) d = distance (m) W = ∆E Work = Energy Change

Answer 25

The rate at which energy is transferred, measured in watts.

Answer 26

P = W / t P = Power (W) W = Work ( J ) t = time (s) P = ΔE / t P = Power (W) ΔE = Change in energy ( J ) t = time (s)

Answer 27

(useful energy/total energy) * 100

Answer 28

P = F/A Pressure (Pa) Force (N) Area (m²)

Answer 29

P = pgΔh P = Pressure (Pa) p = Density (kg/m³) <-- Needs to be kg/m³ for Pa g = gravitational field strength (9.8 m/s²) Δh - Change in depth (m)

Answer 30

Look at the bottom of the meniscus (curve of the liquid).

Answer 31

A measurement with a size (magnitude) and no specific direction.

Answer 32

A quantity with a size (magnitude) and a direction.

Answer 33

Distance, Speed, Time, Mass, Energy and Temperature.

Answer 34

Force, Weight, Velocity, Acceleration, Momentum, Electric field strength, Gravitational field strength

Answer 35

The distance travelled per unit time.

Answer 36

The rate of change of velocity of a body, measured in m/s2.

Answer 37

You need a force to act at right angles (perpendicular) to motion to make an object turn in a circle.

Answer 38

- The mass of the object increases - The speed of the object increases - The radius of the circle decreases

Answer 39

A force between two surfaces when in contact. It impedes motion and results in heating.

Answer 40

A turning force.

Answer 41

A system will not rotate if the clockwise and anti-clockwise moments are equal.

Answer 42

1/2 mv² = mgh 1/2v² = gh

Answer 43

Efficiency = (useful power output / power input) * 100%

Answer 44

A measure of the compression, or 'outward push' from a substance. It is defined as the force per unit area.

Answer 45

Most energy comes from burning fuels (usually fossil fuels ( coal, oil or gas )) Burning the fuel transfers the energy from the chemical store to heat. 1. Source of heat (fuel) is used to boil water. 2. As the water boils, it turns into a high pressure steam. 3. The steam flows through pipes to turn a turbine. 4. After the steam has spun the turbine, it is cooled in a condeser and reenters the boiler system as water to be used again.

Answer 46

A nuclear power plant is similar to a coal / gas power station, but instead of burning a fossil fuel, it uses a nuclear reaction to produce energy. Pros - No CO2 or other greenhouse gases produced. - Each kg of fuel contains large amounts of energy (high energy density) Cons - Uranium is a finite resource and so it is non-renewable. - Nuclear power produces radioactive waste, which is difficult to dispose of and can damage local environments if not dealt with properly. - There is a small risk of nuclear accidents. However, the consequences of an accident are very severe, causing death and disease to humans and animals and contaminating the area for a long time. - Because of stringent safety precautions and complex machinery, power plants are expensive and take a long time to build. They are also extremely expensive to decommission (take apart once they are past their lifetime).

Answer 47

This involves building a dam wall on a river. By holding the water behind the wall, a large height difference can be achieved between the water upstream and downstream. Hydroelectric power relies on the water rushing downstream, through pipes with turbine blades, which generate electricity Pros - The water always flows, so electricity can be produced 24 hours a day. - No carbon dioxide or other greenhouse gases produced. - Renewable - the water is constantly replenished by rainfall. Cons - When the dam is first built it floods large areas of land, which damages or destroys habitats and homes. - The flow of water downstream of the dam can be reduced, which can sometimes change or destroy habitats.

Answer 48

Tidal power uses the same principle as hydroelectric power, but instead of trapping river water, it traps seawater behind a dam (barrage) wall. Water at high tide is trapped behind the barrage to produce a flow of water through turbines, which generate electricity. Pros - The flow of tides is a naturally recurring process. This is a renewable resource. - No carbon dioxide or other greenhouse gases produced. - Tides are easy to predict. - High power output. Cons - Only some places have big enough tidal changes to produce sufficient electricity in this way. - Tidal dams and machines can damage marine ecosystems and habitats. - Blocks large areas of the sea.

Answer 49

Wave power uses the movement of waves up and down to drive turbines, and to produce electricity. Pros - Renewable, Sustainable + no greenhouse gases - Good energy conversion - Simple maintenance - Good in remote areas Cons - May damage wildlife + ecosystem. - Coastal erosion rates may increase - Weak in bad weather - High maintenance costs.

Answer 50

Solar panels are black surfaces that absorb infrared electromagnetic waves from the Sun to heat water for homes. Solar cells produce electricity directly from electromagnetic waves in sunlight. This can be transmitted through power lines to homes across the world. Pros - Ecofriendly - May increase value of your home Cons - Weather dependent (needs sunlight) - Expensive - Producton may be harmful to the environment - Takes up a lot of space.

Answer 51

Wind turns the turbines. Pros - The wind is a renewable resource - it will not run out. - No carbon dioxide or other greenhouse gases produced. - Turbines are comparatively easy and cheap to produce. - Once the turbines are built, the wind has no cost, you only need to pay for maintenance. Cons - Some people think they look and sound unpleasant. - You need a lot of turbines to produce a significant amount of power, so they need to be spread over a lot of land or sea. - Some days are windier than others, so the wind power is unpredictable.

Answer 52

If you live a country with volcanic activity, such as Iceland or Japan, you may know that it is possible to tap into the hot rocks underground. Cold water is fed through pipes underground and returns as steam due to the volcanic activity. The steam drives turbines to generate electricity. Pros - Ecofriendly Cons - Restricted locations

Answer 53

Nuclear fusion takes place in the sun. Currently we are trying to figure out how to do that. Most of our energy comes from the sun. Plants use sunlight for food --> Animals use plants for food --> both become fossil fuels --> used in combustion. Also wind and wave energy is produced by the sun heating hte atmosphere and producing convection currents.

Answer 54

Nuclear power - Energy comes from within atoms. Tidal power - Motion of the sea caused by gravity between the moon and the earth. Geothermal power

Answer 55

Nuclear power - Energy comes from within atoms. Tidal power - Motion of the sea caused by gravity between the moon and the earth. Geothermal power - Comes from hot rocks underground, and is tapping into the internal energy stored in molten rocks deep in the Earth.

Answer 56

Pros - high power output - 24 hours a day output - cheap to build Cons - non-renewable - produces greenhouse gases

Answer 57

×1000000000

Answer 58

1cm² = 0.0001 m²

Answer 59

An object remains in the same state of motion unless a resultant force acts on it. If the resultant force on an object is zero, it means... - A stationary object stays stationary - A moving object continues to move at the same velocity (at the same speed and in the same direction)

Answer 60

Whenever two objects interact, they exert equal and opposite forces on each other. ASK MR. GARDINER

1. Motion, Forces and Energy Flashcards

1.1 Physical quantities and measurement techniques 1.2 Motion 1.3 Mass and weight 1.4 Density 1.5 Forces 1.6 Momentum 1.7 Energy, work and power 1.8 Pressure (89 cards)