1. P6 Science Supplementary 13 July 11
Energy Conversion
P6 Science Supplementary
13 July 11

2. A. Getting basic terms right B. Clarify misconceptions
TODAY
A. Getting basic terms right
B. Clarify misconceptions
C. Explore examples of energy conversion

3. 1. Forms of Energy vs Sources of Energy
(for producing electricity)
1. Light
2. Heat
3. Sound
4. Electrical
5. Kinetic (moving objects)
Wind
Running water
Solar (Sun)
Geothermal
Tidal
Nuclear
Fossil fuels
Electricity
(secondary source)
6. Potential
Eg.Gravitational potential
Chemical potential
Elastic potential

4. 1 (a) Besides being a form of energy, electricity (electrical energy) is a also a source of energy. But it is a secondary source.

5. 1 (b) Is chemical potential energy a source of energy
1 (b) Is chemical potential energy a source of energy? Yes, it can be eg. Food
( c) Can gravitational potential energy be a source of energy? Yes, it can be. Water in a reservoir behind a dam.

6. ----------------------- Green leaf example:
2. Chemical Energy vs Chemical Potential Energy
A bus uses CHEMICAL ENERGY to move. (Or the bus uses chemical energy stored in petrol.)
The petrol has CHEMICAL POTENTIAL ENERGY.
The battery has chemical potential energy.
Green leaf example:
Light energy  Chemical energy
The chemical energy is stored. The energy stored in green leaves is chemical potential energy.

7. Please get the terms right!
3. Gravitational Potential Energy = Gravitational Energy ?
Gravitational Potential Energy = Gravitational Force?
What is a force? What is energy?

8. (a) A falling stone posseses
4. The use of ‘’ & ‘+’
(a) A falling stone posseses
Gravitational Potential Energy and Kinetic Energy
Is it correct to write the following to represent the above:
gravitational potential energy kinetic energy
This statement is not about ENERGY CONVERSION. It is asking about what
forms of energy a falling stone possesses / has.

9. OR ? 4 (b) What is the difference?
Electrical energy  Chemical energy + heat energy
Electrical energy  Chemical energy Heat energy ? OR

10. 5.Any difference between the following?
(a) Light vs Light Energy
(b) Sound vs Sound Energy
(c ) Heat vs Heat Energy
I see light at the end of the tunnel vs I see light energy ….
The electrical energy in the electric train is converted into…
Electrical energy kinetic energy+ light energy+ heat energy+ sound energy

11. 6. Energy ‘used up’? Correct?
When something is used up, it disappears.
In the case of Energy, it does not disappear, it is transferred/ converted.

12. 7. (a) A ball bounces lower because it does not have so much force.
A ball bounces because it has energy. However, it bounces lower and lower because some energy has been transferred / converted to sound energy and heat energy.
BOUNCING BALL

13. BOUNCING BALL
(b) It bounces lower because there is friction. (air resistance?)
Friction slows down the movement of a rolling ball…because of the surface of the floor/ ground/ table with the ball. ** However, there is some air resistance. BUT it is much less compared to a much bigger surface area eg. A piece of paper (same mass)

14. BOUNCING BALL
(c ) Gravitational force will also get lower, therefore the ball bounces lower. What is gravitational force? (gravity)
(d) Gravitational potential energy acts in the opposite direction of kinetic energy. (gets pressurised?) Only forces act in opposite directions.

15. LET’S NOW EXPLORE DIFFERENT CONTEXTS

16. Diving into the pool

17. Solar powered structure

18. Roller Coaster

19. Weight-lifting

20. Bungee Jumping