# 3.3 Work, Energy and Power Flashcards Preview

## Physics A Level > 3.3 Work, Energy and Power > Flashcards

Flashcards in 3.3 Work, Energy and Power Deck (8)
1
Q

Define work done (2)

A

Force x distance moved in direction of force

Energy transferred

2
Q

What is energy?

A

The capacity to do work

3
Q

What is the principle of conservation of energy?

A

The total energy of a closed system remains constant; energy can never be created or destroyed, but it can be transferred from one form to another

4
Q

What is kinetic energy? (2)

A

1/2 x mass x velocity^2

The energy due to the movement of an object

5
Q

What is gravitational potential energy? (2)

A

mass x g x vertical height difference (in a uniform gravitational field)
The energy due to the position of an object in the Earth’s gravitational field

6
Q

When does ΔGPE = ΔKE?

A

When no resistive forces are involved

7
Q

What is power? (2)

A

Work done / time (or force x velocity)

The rate of work done

8
Q

How is efficiency calculated?

A

(Useful output energy / total input energy) x 100