1. 1) Name the 9 types of energy giving examples.
Answer
Electricity
Light
Sound
Kinetic
Nuclear
Thermal
Gravitational potential energy
Elastic
Chemical

2. 2) Name the two types of stored Energy. (2)
Answer
Potential energy eg: Elastic and gravitational
Chemical energy eg: food, fuels and batteries

3. 3) What is the conservation of energy (2).
Energy cannot be created or destroyed and can only be converted from one form to another.
For example all energy supplied to a system needs to be accounted for.
If 300J of electrical energy is supplied to a system, the total useful energy and wasted energy must equal 300j

4. Solar panel (Light to-- Electricity)
4) Explain how energy is conserved in the following ;
Solar panel (Light to--______)
Falling object (Gravitational potential -______)
TV (Electrical ----- ______ +________)
Batteries (Chemical-- _________ __________
Ans:
Solar panel (Light to-- Electricity)
Falling object (Gravitational potential -Kinetic)
TV (Electrical ----- Sound + Light)
Toy car batteries (Chemical-- Electrical  Kinetic .

5. a) Energy could be wasted eg as heat or sound
5) Why is the total input energy not the same as the useful output energy?
Ans:
a) Energy could be wasted eg as heat or sound

6. 6) What kind of energy transfers happen to a person who is running (2).
Chemical energy(food) to kinetic energy (movement

7. Answer Useful energy = 500-300= 200W
7) A machine has an input of 500W. It wastes 300W. (3)
Calculate the useful energy
b) Calculate the efficiency.
Answer
Total input energy= Useful energy+ wasted energy.
Useful energy = = 200W
b) Efficiency= useful = 0.4 or 40%
Total input 500

8. 8)
Calculate the energy supplied
What form is the energy wasted?
What is the efficiency of the light bulb?
Light bulb
Energy supplied
300 J of light energy
30 J of wasted energy
Answer
Total input energy= Useful energy + wasted energy.
= = 330
b) Heat
c) Efficiency= useful = 0.91 or 91%
Total input

9. 9) For an object to stay at the same temperature what needs to happen.
Answer
The energy absorbed must = The energy emitted Or
Power absorbed must = The power emitted

10. 10) a) Describe how the earth is kept at a constant temperature.
b) Describe why a radiator will reach a constant temperature.
Answer
The amount of heat absorbed by the earth from the sun will become equal to the amount of heat emitted.
The amount of heat supplied will equal to the amount of heat emitted (lost)

11. Answer a) Black 11) Which colours are the best absorbers and emitters
White
Silver
Answer
a) Black

12. Answer Mat/rough 12) What type of materials are the best absorbers.
Shiny/gloss
Answer
Mat/rough

13. Heat radiation from the sun is absorbed by the black surfaces.
13) Why are solar panels painted black(6)
Answer
Heat radiation from the sun is absorbed by the black surfaces.

14. 14) Why is a silver coloured blanket used by athletes to cover themselves after a race?
Answer.
The silver colour helps to stop the body heat from radiating away keeping the athlete warm.

15. Answer Conduction Convection Radiation
15) What are the three ways energy is transferred.(3)
Answer
Conduction
Convection
Radiation

16. 16) The thermal heat is transferred to earth from the sun by (infra red) radiation. Why is thermal heat not transferred through convection or conduction (3).
Answer
Convection and conduction require particles, radiation does not. As there are no particles in space (vacuum) convection and conduction cannot happen.

17. Paint the solar panels black Cover pipe with insulation.
17) Solar hot water panels contain water pipes. At the start the temperature of the water in the pipe increases. After a while, the temperature becomes constant.
Suggest changes which would increase the constant
temperature reached.
Answer
Paint the solar panels black
Cover pipe with insulation.

18. 18)
Using the information in the diagram, describe the energy transfers involved in producing electrical energy in a fossil fuel powered power station.
Answer
Heat and light energy supplied by the sun,
for photosynthesis of plants, or energy for animals stored as chemical energy
plants and animals die over million years become fossil fuels
Fossil fuels (chemical energy) burnt to produce thermal energy,
to boil water produces steam.
Steam (kinetic energy) turns turbine,
this turns generator ((kinetic energy) which produces electricity
Underlined and in bold are the energy transfers