1. Forms of Energy

2.  Besides potential and kinetic energy, scientists also classify energy into other forms such as: solar energy which is either light or heat, chemical energy, mechanical energy, electric energy, sound energy, or thermal energy.

3.  Solar energy – energy that comes from the sun as light or heat.  Light – radiation that we see. (the flame of a candle that you see)  Heat – radiation that we feel. (the flame of a candle that you see)

4.  Energy from the sun travels as radiation.  The sun produces several kinds of radiation: light, heat, and radio waves.  How does solar energy help us?  What would happen if we did not have solar energy?

5.  Chemical energy – energy that is released through a chemical reaction.

6.  When it is not being used, chemical energy is potential energy.  A chemical reaction is needed to change this potential energy into kinetic energy.

7.  Many substances release energy in this way.  Can you think of some examples?

8.  Burning is a chemical reaction that releases energy.  If you set a burning candle under a dry twig, what will happen?  If you set a burning candle under an iron bar, what will happen?  What does this tell you about the chemical energy stored in different materials?

9.  Mechanical energy – the combination of all the potential and kinetic energy that something has.

10.  The windup toy in the photo has a key attached to a spring.

11.  When you turn the key, you wind up, or tighten, the spring.  What kind of energy is this?  What happens when the key is released?

12.  What is the toy’s kinetic energy?  Does the toy still have potential energy as it is moving?

13.  Electric energy – the energy that comes from an electric current; also known as electricity.

14.  Lay your head down on your desk, pretend you are at home and a thunderstorm comes and knocks out your power. You are now in a blackout.  What electrical inconveniences do you have?

15.  What kind of energy does a hand- held video game use for power?  What do you have to do to a hand- held video gam in order for it to work?  What kind of energy comes out of the batteries?

16.  Sound energy – energy in the form of vibrations that travel through matter

17.  When you speak, sound energy from your voice meets air molecules and starts them vibrating.  They, in turn, make molecules next to them vibrate, and those make others vibrate.

18.  That’s why our voice can be heard anywhere in the room.  Suppose I’m speaking loud enough to be heard in the hallway, even though the door is closed. What happens when the air molecules next to the door start vibrating?

19.  If you place you hands on the radio or television, you can feel the sound vibrations.  Some people with hearing disabilities have been able to become dancers by feeling the vibrations of the music through their feet.

20.  Thermal energy – energy associated with temperature; heat energy

21.  Remember that all matter is made up of tiny particles that are always moving.  Since they move, they have kinetic energy; also known as thermal energy.  The faster the particles move, the more thermal energy the matter has.

22.  Can you give some examples of thermal energy?

23.  Law of conservation of energy – energy can never be made or destroyed, but it can change forms.

24.  Often, one form of energy changes into another form.  The batteries in a flashlight contain chemical energy, but the flashlight bulb gives off light. Where does the light come from?

25.  The batteries’ chemical energy changes into electric energy.  Then the bulb in the flashlight changes the electric energy into light energy.