# Topic 7 & 8 - Forces Doing Work and Forces and their Effects COMPLETE PK Flashcards

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1
Q

1 What are the units for energy?

A

joules

2
Q

2 How is energy transferred to a light bulb?

A

by electricity

3
Q

3 How is energy transferred away from a light bulb?

A

by light, by heating

4
Q

4 Describe one other way in which energy can be transferred.

A

by sound, by forces

5
Q

5 What is a force?

A

a push or a pull

6
Q

6 What are the units for measuring forces?

A

newtons

7
Q

A

the force of gravity pulling on you

8
Q

8 What does work done mean in physics?

A

energy transferred by a force

9
Q

9 What does power measure?

A

how fast energy is transferred/work is done

10
Q

10 What are the units for power?

A

watts

11
Q

11 What does work done mean?

A

energy transferred by a force

12
Q

12 What are the units for work done?

A

joules

13
Q

13 How do you calculate work done?

A

Multiply force by distance moved in the direction of the force.

14
Q

14 What does power mean?

A

how fast energy is transferred

15
Q

15 What are the units for power?

A

watts

16
Q

16 How do you calculate power?

A

work done divided by time

17
Q

17 Two people with the same weight go up a flight of stairs. How can you tell which one has exerted more power?

A

the one that went up fastest

18
Q

18 Name two non-contact forces.

A

two from: gravity, magnetism, static electricity

19
Q

19 What is a magnetic field?

A

the space around a magnet where it can affect things

20
Q

20 What is a vector quantity?

A

a quantity that has both magnitude and direction

21
Q

21 Name two contact forces.

A

any two from: normal contact force, upthrust, air resistance, etc.

22
Q

22 Name three non-contact forces.

A

gravity, magnetism, static electricity

23
Q

23 How is a force represented in a diagram?

A

arrow showing direction, with length indicating size

24
Q

24 What are the units for measuring force?

A

newtons

25
Q

25 Why is weight a vector quantity?

A

It has a direction as well as a magnitude.

26
Q

26 The Earth attracts the Moon via gravity. What is the other force in this action?reaction pair?

A

the Moon attracting the Earth

27
Q

27 What is the name for the space around an object where it attracts things with mass?

A

a gravitational field

28
Q

28 What is the name for the space around something with an electric charge where it can affect other objects?

A

an electrostatic or electric field

29
Q

29 What is the name for a single force that represents the combined effects of all the forces on an object?

A

a resultant force

30
Q

30 What is the name for a diagram where a measurement on the diagram represents a larger measurement in real life?

A

a scale diagram

31
Q

What is the acronym used for remembering the different types of energy?

A

GEEKS LUNCH (the U doesn’t stand for anything!!)

32
Q

What does the G in GEEKS LUNCH stand for?

A

Gravitational potential energy

33
Q

What do the Es in GEEKS LUNCH stand for?

A

Electrical energy and elastic potential energy

34
Q

What does the K in GEEKS LUNCH stand for?

A

Kinetic (movement) energy

35
Q

What does the S in GEEKS LUNCH stand for?

A

Sound energy

36
Q

What does the L in GEEKS LUNCH stand for?

A

Light energy

37
Q

What does the U in GEEKS LUNCH stand for?

A

NOTHING

38
Q

What does the N in GEEKS LUNCH stand for?

A

Nuclear energy

39
Q

What does the C in GEEKS LUNCH stand for?

A

Chemical energy

40
Q

What does the H in GEEKS LUNCH stand for?

A

Heat (thermal) energy

41
Q

Most things involve only/more than one type of energy

A

More than one

42
Q

Give 3 types of energy found in a phone?

A

Any 3 from electrical energy going in, chemical energy being stored, heat energy, light energy and sound energy going out

43
Q

What type of energy is stored in a match?

A

Chemical energy

44
Q

What type of energy is used to strike a match?

A

Kinetic energy

45
Q

What types of energy come out of a match?

A

Heat, light and a bit of sound

46
Q

What type of energy are fireworks stored as?

A

Chemical

47
Q

What type of energy are fireworks transferred into as they move up?

A

Kinetic

48
Q

What type of energy are fireworks stored as as they explode?

A

Heat, light and sound

49
Q

What type of energy are fireworks stored as as they start to fall/fall back down?

A

Gravitational potential energy and then kinetic energy

50
Q

What does the law of conservation of energy tell us?

A

Energy cannot be created or destroyed, only transformed into another type of energy

51
Q

Energy can/cannot be created or destroyed

A

cannot

52
Q

True/False: Energy can be transformed into another type of energy

A

True

53
Q

True/False: Energy cannot be wasted

A

False, it can be wasted

54
Q

What is wasted energy?

A

Energy that comes out of a situation that we didn’t intend to be there

55
Q

What is the useful energy that comes out of a light bulb?

A

Light

56
Q

What is the wasted energy that comes out of a light bulb?

A

Heat and sound

57
Q

Wasted energy __________ into the surroundings

A

dissipates

58
Q

What happens to energy when it dissipates into the surroundings?

A

It spreads out so much that it can’t be collected and used. It’s not gone - it’s still there. It is just spread out

59
Q

How do we visually show the efficiency or something?

A

A sankey diagram

60
Q

Work done =

A

force x distance

61
Q

What is work done measured in?

A

Joules

62
Q

What is force measured in?

A

Neutons

63
Q

What is distance measured in?

A

metres

64
Q

What is a joule equal to in terms of neutons and metres

A

1 Nm

65
Q

Change in gravitational potential energy =

A

Mass x gravity x change in height

66
Q

What is gravitational potential energy measured in?

A

Joules

67
Q

What is the gravity on earth?

A

10N

68
Q

Kinetic energy =

A

1/2 x mass x velocity squared

69
Q

What is kinetic energy measured in?

A

Joules

70
Q

What is mass measured in?

A

kg

71
Q

What is velocity measured in?

A

m/s

72
Q

Power =

A

Energy transferred / time

73
Q

What are the units for power?

A

Watts

74
Q

Efficiency = (in terms of power)

A

Useful power out / total power in

75
Q

Efficiency = (in terms of energy)

A

Useful energy out / total energy in

76
Q

Efficiency can be expressed as a percentage or a…

A

decimal

77
Q

What is a scalar quantity?

A

Just a number

78
Q

What is a vector quantity?

A

A number and a direction

79
Q

Is distance a scalar or vector quantity?

A

Scalar

80
Q

Is mass a scalar or vector quantity?

A

Scalar

81
Q

Is displacement a scalar or vector quantity?

A

Vector

82
Q

Is weight a scalar or vector quantity?

A

Vector

83
Q

Is speed a scalar or vector quantity?

A

Scalar

84
Q

Is velocity a scalar or vector quantity?

A

Vector

85
Q

Is acceleration a scalar or vector quantity?

A

Vector

86
Q

Is force a scalar or vector quantity?

A

Vector

87
Q

Is momentum a scalar or vector quantity?

A

Vector

88
Q

What is the resultant force?

A

Difference between forces