Download Potential and Kinetic Energy

Potential and Kinetic Energy
What is energy?!
• Capacity to do work
• Measured in joules (J)
Potential Energy
• Energy stored in an object
– Dependent upon:
• Position – top of a hill vs bottom of a hill
• Shape - stretched rubber band, compressed spring
• Condition – old battery vs new battery
• Commonly used as fuel to “run” things
• Ex: batteries, gasoline/fuel, food, object at
the top of a hill, acorn hanging on a tree, etc.
Types of PE
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Chemical (food, gasoline, other fuels)
Nuclear (fission, fusion)
Gravitational (one object above another)
Stored mechanical (elastic PE)
Kinetic Energy
• Energy of an object due to its motion.
– Dependent upon:
• Mass – bowling ball vs a marble
• Speed – car traveling at 75mph vs 25 mph
• Ex: person running, Frisbee flying, baseball
moving through air, car traveling down road
Forms of KE
• Sound – travels in waves, must have
something to travel through
• Radiant – travels in waves, doesn’t have to
have a medium
• Electrical – when e- move (lightning,
electricity)
Law of Conservation of Energy
Energy can be neither created, not destroyed
BUT can change from one form to another.
(Amount of energy in a system remains
constant!)
KE can change to PE, or vice versa!
Energy can be transferred as work and heat 
thermodynamics