1. Work done is measured in ...
- A) joules
- B) watts
- C) coulombs
- D) newtons
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2. Which of these is NOT a store of energy?
- A) chemical
- B) gravitational potential
- C) friction
- D) kinetic
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3-9. Choose the correct energy store in the following sentences:
| A bow and arrow transfers
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| energy into useful
energy. |
| A car petrol engine transfers
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| 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.
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| 10. What is 60 000J in kJ? |
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| 11. How efficient is the motor? |
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| 12. If it converts this energy in 15 seconds, what is the useful power output? |
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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
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14. A tractor pulls a plough 2km across a field using a force of 8kN. What is the work done? |
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15-16. What are the missing labels on this energy flow diagram for a desk lamp?
(All labels show energy transfers). |
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electrical
energy
5000J |
 |
light energy
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4200 J of wasted
energy |
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