PhysicsEnergy

Law of Conservation of Energy• energy cannot be created or destroyed

only transferred from one form to another

Electric Light Chemical Mechanical

2 forms of mechanical energy

1. Kinetic energy (KE)

-energy due to motion

KE = ½ mv2

(J) (kg)(m/s)2

m is the mass of the object in kg

v is the velocity in m/s

2. Potential energy (PE)-energy due to position or conditionex: book high on a shelf

stretched rubber band wound up clock

Known as gravitational potential energyPE = m g h(J) (kg)(m/s2)(m)

m is the mass of the object in kgg is the acceleration due to gravity 9.81m/s2

h is the height in m

Check up:

• Where does the pendulum have greatest PE?

• Where does the pendulum have greatest KE?

Greatest PE

Greatest PE

Greatest KE