Ch 15 Notes

Energy

- The ability to do _______________ (_____________________)

- measured in ______________

Types of Energy

Kinetic Energy (______)

    - Energy of motion

    - KE= ___________________

The faster and object moves (_______) and the heavier it is (_______) gives it more KE

Potential Energy (______)

-stored energy due to _____________ or ________________

-position- the higher an object is = __________________

PE = mgh

m=________                g=_____________                h=_______________

-shape- bending or stretching an object can store energy (rubber bands)

Forms of Energy

1. ____________________- moving objects (not looking at atomic level)

2. ___________________- movement of atoms, related to heat

3. __________________- dealing with movement of electrons/electric charges

4. __________________- energy trapped in bonds (gas, coal, bread, apples)

5. __________________- energy from the strong and weak force

1. ___________- splitting an atom  (power plants use U)

2. ___________- joining atoms  (sun combining H's into He’s)

6. ___________________- spectrum found on pg 540 of book (UV, xrays, visible light, radio waves)

Energy Conversions

Energy can be converted from one form to another

Striking a Match         --> Match Lighting               --> Heating the Air

________________--> ________________--> _____________________

Law of Conservation of Energy- Energy __________________________________, only transferred from one form to another.

Mechanical Energy

• (KE + PE)________ = (KE + PE)________

• - A diver on the board has no velocity ( so their beginning KE is 0), but they have lots of height (so their beginning PE is very high)

•  Just before they hit the water their velocity is very high (so the end KE is high), and their height is almost 0m (so their end PE is almost 0)

• PE at the _________________ is converted to KE at the _____________

• _______________ = ________________

Energy and Mass

- energy and mass are basically different forms of the same thing and can be converted into one another.

-_________________ made this famous with

                            E    =    m    c2

           ______________ =  _________ x (_______________)2

* a little bit of mass can turn into massive amounts of energy.

Energy Resources

How we get our energy

_____________ Energy- energy that can be replaced in a relatively short period of time.

____________________ Energy- generally fossil fuels, can not be replenished at the rate that we are using them.

Coal

Pros-

• _____________
• We can get it in the U.S.
• How we get most of our ___________________________

Cons

• _____________________
• Mining is tough on environment
• Nonrenewable

Oil

Pros

• Provide _____________________ for the price and mass

Cons

• _____________________
• Nonrenewable
• Not enough in this country _______________________

Solar

Active/Solar Panels

Cons

• Only works _________________________
• Not efficient
• Doesn’t give as much energy as ___________________

Pros

• Clean/Renewable

Passive-Water heating on roof, South facing homes, etc.

Pros

• ____________________
• Cheap
• Renewable

Cons

• Won’t _____________________
• Only acts as a supplement

Biomass-using the chemical energy stored in _____________________

Pros- energy can be produced locally

• Ex- burning wood, collecting methane from cow manure, ___________________

Cons

• Takes more energy to make energy

Hydroelectric-using dams to force water to turn a ____________ to make electricity

Pros

• ______________________
• Clean, no fossil fuels

Cons

• Changes river ecology- fish, plants, people

Wind

Pros

• _________________
• Clean energy

Cons

• ____________________________
• Only works in windy areas
• Noisy/birds

Hydrogen Fuel Cells

Pros

• Renewable
• Water is the ____________________
• Fuel is Hydrogen, which is found everywhere

Cons

• Not efficient
• Still science fiction in terms of efficiency

Geothermal

• ____________________- using the heat from magma to boil water, make steam, run turbines for electricity
• Only works in areas near surface magma

• ____________________- stealing the heat from regular ground water, to heat buildings

Nuclear

Fission-_______________ U atoms, capturing the heat to boil water and make electricity

Pros

• High energy for only a _______________

Cons

• _____________________
• Radioactive waste

Fusion-combining _________________ atoms to make energy (how our sun works)

Cons

• Not efficient
• Still science fiction with efficiency