Energyyyyyyyyy

1. Energyyyyyyyyy What is it???

2. Our Good Friend… Energy electricity Energy part 2 Generator Energy part 3

3. The basics-2 types of energy • Kinetic Energy • Energy of motion • All moving objects have kinetic energy • It increases with mass and speed • Consider bowling with a bowling ball vs tennis ball.

4. Potential Energy • Stored energy (has the potential to move) • Energy that an object has due to it’s position (up in the air) • There really is no such thing as “zero potential energy” but for our purposes we’ll say that anything on the ground has a potential energy of “0”

5. Law of conservation of energy • States that energy can neither be created nor destroyed BUT it can change form. • From kinetic to potential and back to kinetic • Examples of this??

6. Video Law of conservation of Energy

7. Other forms of energy… • All energy is either a form of kinetic or potential (or both) • But there are a few more types of energy that fall under these categories. • Mechanical- sum of an objects kinetic and potential. • Example: moving car • Sound energy- caused by the vibration of particles in a medium such as steel, water, or air. • Guitar • How do we hear the noise if it’s just vibrations? Answer Ellen

8. Forms of energy (cont) 3. Electromagnetic- a. x-rays, microwaves, cell phones, our sun 4. Electrical energy a. This is why we have lights. Negatively charged particles (electrons) move down a positively charged wire. This gives us an electrical current. 5. Chemical energy- food, batteries, matches

9. Energy (cont) 6. Thermal energy- particles move faster at higher temperatures than at low temperatures. We feel this as heat a. No such thing as cold…just a lack of thermal energy(heat). Cold is just a feeling our brain 7. Nuclear energy- source of nuclear energy comes from the nucleus of an atom (hence, atom bomb) a. how does the sun work? Cold Fusion

10. Energy Transfer • Don’t get freaked out by “science words”. Break it down: The transfer of energy from one place to another. • 3 ways to transfer heat from one place to another: Can you think of any?

11. 3 ways to transfer heat energy… • Conduction • Transfer of energy as heat from one substance to another through direct contact. Example: metal spoon in hot chocolate. Heat is conducted from hot part of spoon to cool end of spoon until entire spoon is same temp. b) Conductors- material that transfers heat very well. Metal is a great conductor. c) insulators-material that does NOT transfer heat well. Examples are wood, paper, plastic foam. Foam has many small spaces that are filled with air…which is why they use foam cups for hot chocolate at football games.

12. Convection • Transfer of energy as heat by the movement of a liquid or gas. • As temperature (of liquid or gas)increases (heats up), the density (of the liquid or gas) decreases. • Common misconception: hot air doesn’t rise, cold air sinks (because its more dense). Think of sleeping in the top bunk at deer camp. It’s always very hot up there. That’s because the hot air is floating on top of the dense cold air.

13. Radiation • Transfer of energy by electromagnetic waves. • Has the ability to travel through empty space. • Sun heats the earth by radiation. • Other examples: microwaves, infrared light, visible light. • All objects emit (release) radiation…even you. It’s considered negligible (so small that we don’t really count it)

14. So how does radiation cause cancer??? (don’t have to write this down…just listen) Ionizing radiation is high-frequency radiation that has enough energy to remove an electron from (ionize) an atom or molecule. Ionizing radiation has enough energy to damage the DNA in cells, which in turn may lead to cancer. Gamma rays, x-rays, some high-energy UV rays, and some sub-atomic particles such as alpha particles and protons are forms of ionizing radiation. Non-ionizing radiation is low-frequency radiation that does not have enough energy to remove electrons or directly damage DNA. Low-energy UV rays, visible light, infrared rays, microwaves, and radio waves are all forms of non-ionizing radiation. Aside from UV rays, these types of radiation are not known to increase cancer risk.