Energy….

1. Energy…. Takes energy to work doesn’t it?

2. So… What is energy? • Energy: the ability to do work. • Does NOT mean you will do the work • It means you have the potential to do the work… • Just because you have the energy to clean the garage (work) doesn’t mean you will do the work • yarp

3. Categories of energy • Kinetic energy (KE) = used energy… energy of motion • Running, moving, actually doing work • Potential energy (PE)= stored energy… energy of position • Unused batteries, squished spring, holding a book in the air • yarp

4. Math… aw yea!!!! • KE = ½ mv2 m = mass V = velocity • PE = mgh m = mass G = 9.8 m/sec2 (gravity) H = height m • Units of both = Joules (same as work) • yarp

5. Try em out!!!! • A 2 kg ball is moving at a velocity of 5 m/sec north. How much kinetic energy? • You hold a 2 kg ball 2 meters high. How much potential energy?

6. Your sweet coaster data

7. More sweet graph data

8. Energy is either being stored or used • You have a new battery potential energy • You plug in the battery and use it… kinetic energy • Whenever energy is changing/moving it is always going to be either: • Kinetic or potential energy • Changing from one to the other • yarp

9. examples • Slinky spring • Pushing a boulder up a hill • Letting the boulder fall down the hill • Wait a sec… yep, our coaster data showed this!!!! • yarp

10. Woa… enough notes for now!!! • Time to do a curvy cpo coaster lab!!!! • Aw yea!!! Lab lablab… • Sweet sweetsweet!!!!! • Lab lablab!!! • Yarpyarpyarp

11. Energy changes and types pt 2

12. Make sure you talked about… • About the marble roller coaster lab first… • Don’t be naughty and skippy poo this!!!! • Show the graphs… talk about energy… love it…. • yarp

13. Energy types… just like force types • 1 Physical/mechanical: energy of motion • using energy to physically move things • 2 Radiant energy: light, radio, U.V. visible electromagnetic waves • 3 Electricity: electrical energy • Could be radiant… • 4 Heat/thermo: heat… always present • Heat: energy moving from warmer to colder things • Could also be radiant • yarp

14. More??? More… • 5 Chemical: energy of chemical reactions • Energy of the making and breaking of chemical bonds • Energy in gasoline, your food, putting a metal in acid. • 6 Nuclear: energy within the nucleus of an atom. (matter converted into energy) • Fusion = combining nucleuses • Sun does this… hydrogen nuclear reactions • Fission = splitting of splitting of nucleuses • Uranium, plutonium bombs • yarp

15. More???? Last one… • 7 Sound: the energy of sound waves. • Sound is the vibration of particles at certain frequencies picked up by your ear. • You can not hear in space/vacuum. • Can be considered physical because the particles are physically moving. • Yarpy!

16. Deserve to conserve • Conservation of energy: energy is not gained or lost… only converted into different forms. • Energy conversions are inefficient. • During every energy conversion heat is produced • Yarp…

17. Example time… • Playing a blu ray dvd through your HDTV • Draw it out!!!! Shout it out… yarp it out!!! • Or… if short on time… skip this and move on to the last 2

18. Example 2… yea! • The starting of a car…. Old skoolcoolio!!!!

19. Example 3… • Using a photovoltaic cell (solar power) to power a fan that has a looped rope tied to it spinning an electrical generator to power a radio.