The document discusses different types of energy including work, power, kinetic energy, potential energy, gravitational potential energy, the law of conservation of energy, and energy conversion efficiency. It provides definitions and equations for calculating work, power, kinetic energy, gravitational potential energy. It also lists examples of energy transfers from one form to another such as electrical energy to light, sound and heat in a television or chemical energy to kinetic, sound and heat in a car engine.

1. Energy
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3. Work
• When a force (Newton, N) moves an object
work is done.
• Work is a measure of the amount of energy
(Joules, J) used in moving the object.
work done = force applied x distance moved
W = F x d
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6. Force Diagrams

7. • Thrust – a forward push
• Upthrust – the upwards force on a body in a
liquid or a gas

9. Power
• Power (Watts, W) is the rate that work is done
– how fast energy is used.
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10. Kinetic Energy
• The energy of motion.
• All moving things have kinetic energy.
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11. Calculating kinetic energy
Ek = ½mv2
m = mass of object (kg)
v = the objects speed (m/s)
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12. Potential Energy
• An object can store energy – this is dependent
on position.
• Includes - gravitational, chemical and elastic
energy.
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13. Electrical Energy Kinetic Energy

14. Kinetic Energy Electrical Energy

15. Electrical Energy Sound Energy

16. Electrical Energy Heat Energy

17. Light Energy Electrical Energy

18. Elastic Energy Kinetic Energy

19. Chemical Energy Heat Energy

20. Gravitational Energy Electrical Energy

21. Gravitational Energy Kinetic Energy

22. Gravitational Potential Energy
Ep = mgh
m = mass (kg)
g = acceleration due to gravity (9.8 m/s2)
h = height (m)
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23. Law of Conservation of Energy
• States that energy cannot be created or
destroyed, just transformed from one form to
another.
– Therefore, energy never
‘disappears’.
– Energy that is transferred to
unwanted forms is wasted energy.

24. Et = Ep + Ek
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25. Energy Conversion Efficiency
• Some energy can be ‘lost’ as heat and sound.
• Energy is lost in the form of heat and sound
each time the rollercoaster moves. If this did
not occur the rollercoaster would keep on
moving forever.

26. Television
Electrical Light, Sound and Heat

27. Stereo
Electrical Sound and Heat

28. Car Engine
Chemical Kinetic, Sound and Heat

29. Energy Transfers - Boardworks
Light Bulbs
Electrical Energy Light and Heat