1. Ch. 3 Energy, work, and simple machines

2. Section 1: Types of Energy
The ability or means to cause a change.
What does this mean to you?
Food
Fuel
Batteries
Light
Nuclear
Solar
Wind

3. Kinetic energy: what is it…..
The energy a moving object has…
EX:
Molecules have kinetic energy too.
Heat is the amount of kinetic energy in a substance.

4. Potential energy: what is it……
Energy of position/ Stored energy
Object that have a height above earth.
Gravitational potential energy
Objects that have “loaded potential”
Stretched rubber band
Drawn bow
slingshot
Chemical potential
Gun powder
Gasoline
Wood for a fire

5. Other forms of energy
Electric: the energy carried by an electric current (moving electrons)
Kinetic energy
Nuclear: energy stored/released from the nucleus of an atom
Nuclear powerplants, nuclear bombs.
Potential energy
Thermal: the sum of the kinetic and potential energy in the molecules
Heat (kinetic) in the molecules + the energy (potential) stored in the bonds

6. More energy…. Sound: energy carried by sound waves
Kinetic energy travels through the air, not the molecules
Radiant: energy carried by electromagnetic waves
Light
Radio waves (fm am xm)
Wi-fi
X rays

7. Section 2: Energy transform and work
Vocab:
Energy transformation
The conversion of energy from one form to another
Gravitational Potential to Kinetic
Chemical potential to heat
Law of conservation of energy
Energy cannot be created or destroyed, it only changes form
Ex: Roller Coaster
Roller coaster depends on electric, magnetic, or another form of potential energy to start. That original g. p.e. powers the rest of the kinetic (fun) energy

8. Roller coaster energy video

9. work Occurs when an object MOVES in the direction of a given FORCE.
Only occurs while the force is contacting the object.
Only occurs in the direction of the force.
Increases the kinetic energy of the object.
Which one is not work?
Carrying books to class.
Lifting milk to your mouth.
Holding the championship trophy over your head.

10. Work = force x distance W = F x D
How much work is done when you carry your books from period 7 to period 8. The books require 50 N of force and your classes are 50m apart.
W= F x D
W = 50N x 50m
W = 2500 N x m or 2500 J

11. Energy transfer and Heat
When energy changes from one form to another, there is always energy loss in the from of HEAT.
Due to friction! The arch enemy!
Light bulbs
Car engines/tires