Topic 8 & 9 Energy, work & power

Question 1

1 What are the units for energy?

Answer 1

joules

Question 2

2 How is energy transferred to a light bulb?

Answer 2

by electricity

Question 3

3 How is energy transferred away from a light bulb?

Answer 3

by light, by heating

Question 4

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

Answer 4

by sound, by forces

Question 5

5 What is a force?

Answer 5

a push or a pull

Question 6

6 What are the units for measuring forces?

Answer 6

newtons

Question 7

7 What is your weight?

Answer 7

the force of gravity pulling on you

Question 8

8 What does work done mean in physics?

Answer 8

energy transferred by a force

Question 9

9 What does power measure?

Answer 9

how fast energy is transferred/work is done

Question 10

10 What are the units for power?

Answer 10

watts

Question 11

11 What does work done mean?

Answer 11

energy transferred by a force

Question 12

12 What are the units for work done?

Answer 12

joules

Question 13

13 How do you calculate work done?

Answer 13

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

Question 14

14 What does power mean?

Answer 14

how fast energy is transferred

Question 15

15 What are the units for power?

Answer 15

watts

Question 16

16 How do you calculate power?

Answer 16

work done divided by time

Question 17

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

Answer 17

the one that went up fastest

Question 18

18 Name two non-contact forces.

Answer 18

two from: gravity, magnetism, static electricity

Question 19

19 What is a magnetic field?

Answer 19

the space around a magnet where it can affect things

Question 20

20 What is a vector quantity?

Answer 20

a quantity that has both magnitude and direction

Question 21

21 Name two contact forces.

Answer 21

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

Question 22

22 Name three non-contact forces.

Answer 22

gravity, magnetism, static electricity

Question 23

23 How is a force represented in a diagram?

Answer 23

arrow showing direction, with length indicating size

Question 24

24 What are the units for measuring force?

Answer 24

newtons

Question 25

25 Why is weight a vector quantity?

Answer 25

It has a direction as well as a magnitude.

Question 26

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

Answer 26

the Moon attracting the Earth

Question 27

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

Answer 27

a gravitational field

Question 28

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

Answer 28

an electrostatic or electric field

Question 29

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

Answer 29

a resultant force

Question 30

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

Answer 30

a scale diagram