2. Prepared by Mrs Ong LK

3. kinetic energy Gravitational potential energy Chemical potential energy Elastic potential energy heat energy light energy Electrical energy Sound

5. The energy that moving things have is called kinetic energy An object that moves fast has more kinetic energy than one that moves slowly For objects of the same mass, the one that moves faster has more kinetic energy For two objects moving equally fast, the one with the greater mass has more kinetic energy The kinetic energy of an object depends on its mass, and how fast the object moves

6. There are many forms of kinetic energy - vibrational (the energy due to vibrational motion), rotational (the energy due to rotational motion), and translational (the energy due to motion from one location to another).

7. Wind and water movements are energy sources that possess kinetic energy

10. Chemical Potential energy can be found in: food fuel – oil, wood, coal and gas batteries

11. It would take millions of rubber bands to move a real airplane, so gasoline is used instead. But you don't stretch gasoline to make it work, you burn it. The chemical makeup (arrangement of molecules) of gasoline makes it a good fuel source. All nonliving and living things, from automobiles to zebras, are made up of molecules. It takes energy to make these molecules and hold them together. The energy stored in molecules is called chemical potential energy. There are many examples of chemical potential energy being converted to kinetic energy to do work. The chemical energy in food is used by our bodies to move. In a lighted firecracker chemical energy is used to make a loud sound and to scatter pieces of the firecracker all over. Chemical Potential Energy

12. Gravitational Potential energy is the energy that is stored in an object because of its position. An object has gravitational potential energy if it is above ground

13. Greater Height Less Height

14. Same Height basketball Bowling ball

15. The gravitational potential energy of an object depends on its mass and on its height from the ground.

16. An object has potential energy when it stores energy Other ways to store energy:

17. Elastic Potential Energy A stretched rubber band has the potential to do work or change things. This form of energy is called elastic potential energy. It occurs when an object (such as our skin, a spring, a trampoline, or a rubber band) resists being stretched out of shape. The elastic potential energy in a rubber band can be used to do work. For example, toy airplanes fly when a rubber band untwists and spins a propeller. The elastic potential energy in the rubber band was converted into kinetic energy.

18. Electrical (Electromagnetic) Potential Energy A battery has chemical potential energy along with electrical potential energy. When you turn on a device that is battery- operated, such as a flashlight or a toy, the electrical potential energy stored in the battery is converted into other forms of energy such as sound, mechanical motion, thermal energy, and light. For an electrical appliance you plug in, the electrical potential energy is maintained by a spinning generator of a power plant, hydroelectric dam, or a windmill. A solar cell stores electrical potential energy similar to a battery as long as the sun is shining on it.

20. Light energy is usually accompanied by heat energy. Light is often produced when an object becomes very hot Sources of light energy: Sun Burning objects Lamps and bulbs

21. We are able to see a light source when light from the source enters our eyes

22. We see an object that is not a light source because some light that falls on the object is reflected into our eyes.

25. Heat is a form of energy that we can feel. Heat energy makes us feel warm or hot. It is given off by: (a)Burning objects (b)Hot objects Heat energy can be used to do work

26. We can also use heat to: (a)Dry things (b)Cook food (c)Melt things (d)Keep warm (e)Move machines

27. Movement

30. Geyser Volcano eruption

31. Temperature is a measure of how hot or how cold an object is. It can measured by a thermometer Heat flows when there is a difference in temperature. Heat flows from a region of higher temperature to a region of lower temperature. Heat cannot be measured by a thermometer

32. Energy from the Sun

34. Comes in the form of electricity

36. Electrical energy can be produced by many sources like power stations, dry cells and solar cells Electrical energy is widely used

37. What forms of energy has the electrical energy been change into?

39. Sound is a form of energy that we hear. We use sounds to communicate We produce sound when we speak or play a musical instrument. We hear because we can detect sound with our ears.

40. Sound energy is produced when an object vibrates. When an object vibrates, it makes the air surrounding it vibrate. The vibrations are called sound waves. We hear sounds when the sound waves reach our ears. strike blow bow pluck

41. How do you think the energy has changes for the following activities?

42. Electrical energy Kinetic energy + Sound energy + Heat energy

43. Chemical potential energy Kinetic energy + Heat energy + sound energy

44. Chemical potential energy Kinetic energy + Heat energy + sound energy

45. Gravitational potential energy Kinetic energy + Heat energy + sound energy

46. Chemical Potential energy Electrical Energy Heat and light energy

47. Light energy Chemical Potential energy

48. Kinetic energy + Light energy + Heat energy + Sound energy

49. Gravitational Potential energy Partial Gravitational Potential energy + partial Kinetic energy Kinetic energy Partial Gravitational Potential energy + partial Kinetic energy Gravitational Potential energy Extra Information How do you think the energy changes at the different positions L to P?