Unit 1 - Motion, forces and energy Flashcards

1
Q

Common units of length

A

mm, cm, m, km

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Common units of time

A

ms, s, min, h, d

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Common units of volume

A

cm^3, m^3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Period

A

The time taken for a full oscillation (start - start)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Vectors

A

Measurements that have specific direction and magnitude

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Scalars

A

Measurements that have magnitude but no specific direction in which they act

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Scalar examples

A
  • Time
  • Speed
  • Pressure
  • Distance
  • Mass
  • Energy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Vector examples

A
  • Velocity
  • Displacement
  • Momentum
  • Weight
  • Acceleration
  • Force
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Average speed calculation

A

Average speed(m/s) = Total distance travelled(m) ÷ Total time taken(s)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Velocity

A

The speed of an object in a specific direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Acceleration

A

The change in velocity per unit time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Deceleration/negative acceleration

A

The negative change in velocity per unit time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Acceleration calculation

A

Acceleration(m/s^2) = Change in velocity (m/s) ÷ time taken (s)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Notation for deceleration

A
  • Negative acceleration e.g. -2m/s^2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Speed

A

The change in distance travelled per unit time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Displacement

A

How far an object is from its starting position in a particular direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Features of a distance-time graph

A
  • Straight sloping line = constant speed
  • Straight loping line of higher gradient = faster constant speed
  • Flat/horizontal line = stationary
  • Gradient = Speed
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Features of a speed-time graph

A
  • Flat horizontal line at zero speed = stationary
  • Flat horizontal line above zero speed = constant speed
  • Upward sloping line = acceleration - steeper gradient = higher acceleration
  • Downward sloping line = deceleration
  • Gradient = acceleration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Figure for acceleration of gravity/acceleration of free fall

A

g = 9.8m/s^2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Calculating distance travelled on a speed-time graph

A

Calculate the area under the line

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Relationship with air resistance and acceleration

A
  • More air resistance = less acceleration
  • More acceleration = more air resistance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Terminal velocity

A

The ‘top speed’ of any object when falling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

When terminal velocity occurs

A

When the downward force of weight is balanced by air resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Weight

A

A gravitational force on an object that has mass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Unit of weight
Newtons
24
Mass
The quantity of matter in an object at rest
25
Unit of mass
Kg
26
Gravitational field strength calculation
Gravitational field strength (N/Kg) = Weight(N) ÷ Mass(Kg)
27
Unit of gravitational field strength
9.8N/Kg - every 1 kg of mass is pulled downwards with the force of 9.8N
28
Gravitational field
A volume of space around where any mass would experience a force
29
Density calculation
Density (Kg/m^3) = Mass (Kg) ÷ Volume (m^3)
30
Density of water
- 1g/cm^3 - Density > 1g/cm^3 will sink - Density < 1g/cm^3 will float
31
How forces can affect am object
- Change its shape - Change its size - Change its velocity - Change its direction of motion
32
Friction
Impeded motion and results in heating
33
Calculating forces
- Forces acting in the same direction = addition - Forces acting in opposing directions = subtraction for resultant force
34
Result of unbalanced forces
- Resultant force --> change in speed
35
Result of balanced forces
- No resultant force --> constant speed or stationary
36
Force calculation
Force (N) = Mass (Kg) x Acceleration (m/s^2)
37
Effects of more perpendicular force / situations needing more perpendicular force
- Mass of object increases - Speed of object increases - Radius of circle motion decreases
37
Need for an object to turn in a circle
A force to act perpendicular to motion
38
Hooke's Law calculation
Force (N) = spring constant (N/m) x extension (m)
39
Limit of proportionality
The point at which when enough force is added, the spring deforms - seen as curve on spring constant graph
40
Moment
A turning force
41
Moment calculation
Moment (Nm) = Force (N) x perpendicular distance to the pivot (m)n
42
How to increase a moment
- Increase size of force - Increase perpendicular distance from the pivot
43
Principle of moments
Total clockwise moment = total anti-clockwise moment
44
Equilibrium
No net moment / no resultant force forces or moments
45
Centre of gravity
The average position of all the mass in that object
46
Centre of gravity in regular shapes
Along the line of symmetry
47
Factors to stability
- Wide base - Low centre of mass
48
Unstable
Center of gravity is not above the base
49
Momentum calculation
Momentum (Kg m/s) = Mass (Kg) x Velocity (m/s)
50
Factors to increases momentum
- Increase velocity - Increase mass
51
Law of conservation of momentum
In any collision, the total momentum before and after the collision is the same
52
Impulse
Change in momentum
53
Impulse calculation
Final momentum - initial momentum
54
Impulse calculation 2
Impulse = Force x change in time
55
Force calculation (impulse)
Force = change in momentum/impulse ÷ change in time
56
Different types of energy
- Kinetic energy - Chemical energy - Nuclear energy - Internal/thermal energy - Electrostatic energy - Elastic energy - Gravitational potential energy
57
Principle of conservation of energy
Energy cannot be created or destroyed, only converted from one store to another
58
Kinetic energy equation
Kinetic energy (J) = 1/2 x mass (kg) x velocity (m/s)^2
59
Gravitational potential energy equation
Gravitation potential energy (j) = mass (kg) x acceleration of gravity (m/s^2) - 9.8 x change in height (m)
60
Work equation
Work done = energy transferred
61
Work done calculation
Work done (J) = Force (N) x distance moved in the direction of the force (m)
62
How electricity if generates
- Water boils into steam - Stream turn a turbine that turns a generator making electricity
63
Nuclear energy
- Uses a nuclear reaction to produce heat
64
Hydroelectric energy
- Water rushing downstream through pipes and turbines to generate electricity
65
Tidal energy
Sea water trapped behind a dam wall to produce flow of water through turbines
66
Wave energy
Movement of waves up and down to produce electricity
67
Solar energy
- Solar panels absorb infrared electromagnetic waves to heat water - solar cells produce electricity from the electromagnetic waves
68
Wind energy
Wind spins a turbine to make electricity
69
Geothermal energy
Water turns to steam due to heat of volcanic activity to spin a turbine
70
Three energy resources not originally from the sun
- Nuclear power - Tidal power - Geothermal power
71
Pros and cons of fossil fuels
Pros: - High power output - 24 hours a day output - Cheap to build Cons: - Non-renewable - Produces greenhouse gases
72
Pros and cons of nuclear energy
Pros: - High power output - 24 hours a day output - No greenhouse gases Cons: - Non-renewable energy - Radioactivity risks - very expensive to build
73
Pros and cons of hydroelectric energy
Pros: - Renewable resource - No greenhouse gases - High power output Cons: - Disrupts animal habitats ad displaces people - Needs a big river - Expensive to build
74
Pros and cons of tidal energy
Pros: - Renewable resource - No greenhouse gases - High power output Cons: - Needs high tides - not common - Blocks large area of the sea - Expensive to build
75
Pros and cons of wave energy
Pros: - Renewable resource - No greenhouse gases Cons: - New technology - not reliable - Low power output
76
Pros and cons of solar energy
Pros: - Renewable resource - No greenhouse gases Cons: - Unreliable - needs sunshine - Low power output - Expensive to build
77
Pros and cons of wind energy
Pros: - Renewable resource - No greenhouse gases - Cheap to operate Cons: - Unreliable - needs wind - Low power output per turbine - Expensive to build
78
Pros and cons of geothermal energy
Pros: - Renewable resource - No greenhouse gases - Reliable output Cons: - Only a few volcanic countries - Relatively low power output
79
Efficiency energy calculation
Efficiency = Useful energy output ÷ energy input x 100%
80
Efficiency power calculation
Efficiency = Useful power output ÷ power input x 100%
81
Power calculation
Power (W) = energy transferred (J) ÷ Time taken (s)
82
Pressure equation
Pressure (Pa) = Force (N) ÷ Area (m^2)
83
Change in pressure equation
Change in pressure = Change in depth of liquid (m) x density of liquid (Kg/m^3) x gravitational field strength (N/Kg)