1. And converting from one type to another

2. ENERGY AND CHANGE When you got up this morning, were you tired or did you have lots of energy? In everyday conversation, the word ENERGY is often used to describe how active or lively something is. In physics, energy is the ability to make changes occur. Energy is a bit like money – you can save it up or you can spend it to make things happen.

3. ENERGY AND CHANGE Movement (or change of position) is one type of change.  Walking/running/jumping  Spinning wheels  Projectiles  Falling objects  Leaves floating down a river

4. ENERGY AND CHANGE Growth (change in size) is another kind of change.  Plants getting taller  Fruit ripening  Humans getting bigger  A balloon expanding

5. ENERGY AND CHANGE Change of phase is also a type of change caused by energy.  Melting ice  Evaporating puddles  Condensing rain  Sublimating CO 2

6. KINETIC ENERGY Anything which is moving has kinetic energy.  Electrons (electricity)  Molecules  Vehicles  Projectiles  Waves (sound, light, ocean)  Explosions

7. POTENTIAL ENERGY Energy stored in matter or resulting from an object’s position is potential energy.  Stretched rubber band  Compressed/stretched spring  Object lifted off of the ground  Stored in chemical bonds (food)  Stored in nuclei (radioactive)

8. KINETIC + POTENTIAL = TOTAL MECHANICAL ENERGY Potential energy can change to kinetic energy and kinetic energy can change to potential energy. Playground swing Roller coaster Bouncing ball. The total energy of an object is known as its mechanical energy.

9. POTENTIALKINETIC

10. HANDS-ON STUFF – PERSON 1 Give a pencil a flip and slide it across the table. As the pencil starts moving, it clearly has energy. It slides to a stop, though. Where did that initial energy go? Don’t shout out the answer – write it down and draw a diagram.

11. HANDS ON STUFF – PERSON 2 Blow up a balloon but don’t tie it off. Let go of the balloon… Draw a diagram of this. Identify (write) the types of energy transformations that just happened.

12. HANDS ON STUFF – PERSON 3 Grab a rubber band and a small wad of paper. Fire the paper wad across the room (without hitting anyone in the eye.) Draw a diagram. Identify (write) the types of energy transformations that just took place.

13. HANDS ON STUFF – PERSON 4 Get two toy cars and roll them toward each other until they crash. Where does all the energy go when they collide and eventually come to a halt?

14. HANDS ON STUFF – PERSON 5 Create a pendulum on a string. Hold the free end with one hand and start the pendulum swinging with the other. Draw a diagram and identify (write) the energy transformations taking place. If you wait long enough (with a steady hand) the pendulum will eventually slow down and then stop altogether. What happened to the energy? Write your guess.

15. WATCH A DOUBLE PENDULUM DEMO Click here to watch coupled pendulum Write your very scientific explanation about the energy transfer you just witnessed.

16. THE SCIENC-EY EXPLANATION We can figure out where the energy went by first figuring out why the pencil slowed down and eventually stopped. The culprit is the force of friction between the pencil and the table. Where did the energy go? To answer that, rub your hands together really fast. Feel the heat? It is generated by the friction between your hands.

17. THE SCIENC-EY EXPLANATION Of course, the pencil and the table don’t STAY warm. The heat is transferred to the surrounding air.

18. THE SCIENC-EY EXPLANATION The air you force into the balloon causes it to change shape by stretching, so you gave the balloon elastic potential energy. When you let go of the balloon, it gradually collapses, forces air out of the opening, and pushes back on the balloon, causing it to go forward. kinetic energy of balloon of air escaping

19. SCIENC-EY EXPLANATION Just like the balloon, you gave the rubber band elastic potential energy when you pulled it back. Then you let it go. This e.p.e. changes to kinetic energy of the paper. The rubber band moves a bit so there’s kinetic energy of the rubber band. Both the rubber band and the paper push on the air molecules, giving them kinetic energy. The energy of the paper wad heats up the victim of the attack when it hits. This thermal energy eventually ends up as energy in the surrounding air. There’s also a definite sound when you let go of a stretched rubber band so that’s sound energy. k.e. rubber k.e. paper sound energy band wad k.e. air thermal energy k.e. air victim thermal energy air

20. SCIENC-EY EXPLANATION If you’ve ever heard a car crash you know there’s lots of sound energy produced. There are also flying car parts moving through the air. Fenders and hoods deform. After everything settles down, though, it’s all at rest. That’s because, due to friction, all the kinetic energies (except sound)eventually turn into thermal energy. k.e. deforming k.e. flying sound parts parts thermal energy thermal energy air air

21. SCIENC-EY EXPLANATION The pendulum is a bit different because the transformations take place within the pendulum itself. When you pull it to the side, you give it gravitational potential energy, let it go and the potential energy transforms to kinetic energy. When the pendulum eventually comes to a stop it is because of friction with air molecules. potential kinetic

22. ALL ENERGY IS EITHER KINETIC  Thermal energy is just kinetic energy of molecules  Sound energy is motion of air molecules = kinetic energy  Radiant (light) energy is movement of packets of light, or photons = kinetic  Electrical energy is the movement of electrons = kinetic energy POTENTIAL  Energy in food is stored in the chemical bonds = potential  The build-up of charge in a cloud (just prior to a lightning strike) is a form of potential energy.  Nuclear fusion and nuclear fission are both the result of energy stored in the nucleus of atoms = potential  Gravitational / Elastic

23. LAW OF CONSERVATION OF ENERGY The total amount of energy in the universe is constant. Energy cannot be created nor destroyed, it can only change from one type to another. This is known as the Law of Conservation of Energy.

24. click here to watch a rockin' science teacher