UNIT 4

Question 1

The principle of conservation of energy

Answer 1

Total amount of energy before and after a change is the same

Question 2

Efficiency

1
2

Answer 2

1 the useful energy output of the device

—

Question 3

Work done = energy transferred

Work done equation

Answer 3

🔺W = F x d

Question 4

Gravitational potential energy = work done

So equation of Work and equation of GDP

Answer 4

Work done = force x distance moved

GDP= mgh

They equal

Question 5

Kinetic energy = GDP

Kinetic energy eqt

GDP eqt

Answer 5

Kinetic Energy = 1

—

Question 6

Power
1
2
3

Answer 6

Power ( w) = Work done ( in joules) / time ( in seconds)

Power ( w ) = useful energy transferred ( joules ) / time takes

P = E
—