1. Work done is measured in...

  • A) joules
  • B) watts
  • C) coulombs
  • D) newtons
 

2. Which of these is NOT a store of energy?

  • A) chemical
  • B) gravitational potential
  • C) friction
  • D) kinetic

3-9. Choose the correct energy store in the following sentences:

A bow and arrow transfers
energy into useful energy.
A car petrol engine transfers
energy into useful energy.
Most of the energy wasted in the car engine
is lost as energy.
A falling ball transfers energy
into energy.

 

A motor on a train converts 60 000J of electrical energy into 45 000J of kinetic energy as the train accelerates.

train

10. What is 60 000J in kJ?
11. How efficient is the motor?
12. If it converts this energy in 15 seconds, what is the useful power output?

13. What is the formula for work done?

  • A) Work done = force x distance
  • B) Work done = force ÷ distance
  • C) Work done = mass x acceleration
  • D) Work done = mass ÷ acceleration

14. A tractor pulls a plough 2km across a field using a force of 8kN. What is the work done?

15-16. What are the missing labels on this energy flow diagram for a desk lamp?
(All labels show energy transfers).
desk lamp

electrical
energy
5000J

sankey arrow

light energy

4200 J of wasted

energy