Topics 7+8

Question 1

Work done def

Answer 1

The energy transferred by a force

Question 2

Work done equation

Answer 2

Work done (J) = force (N) times distance moved in the direction of the force (m)

Question 3

Power def

Answer 3

The rate at which energy is transferred / the rate of doing work

Question 4

What’s power measured in and what does this mean?

Answer 4

Watts (W)

1 Watt means 1 joule of work done per second.

Question 5

Power equation

Answer 5

Power (W)= work done (J) divided by time taken (s)

Question 6

Contact forces

Answer 6

Forces between touching objects

Upthrust

Question 7

Non contact forces

Answer 7

Forces between things that aren’t touching
Gravity
Magnetism
Static electricity

Question 8

What’s gravity and give example

Answer 8

A force that occurs between any two objects that have a mass.
The moon stays in orbit around the earth because the two bodies attract each other.
The force of the moon on the earth is the same size as the force of the earth on the moon, but in opposite directions.

Question 9

Action-reaction forces

Answer 9

Pairs of forces acting on different objects, in opposite directions

Question 10

Why do the moon and earth affect each other

Answer 10

The moon is within the earths gravitational field (the space around an object where it can affect another object).