BELLWORK 2/01/17 From the work-kinetic energy theorem, we see that the speed of an object ______ if the net work done on it positive, because the final kinetic energy is greater than the initial kinetic energy.

ANSWER Increases

Potential Energy

How is all energy divided? Potential Energy Kinetic Energy Gravitation Potential Energy Elastic Chemical

What is Potential Energy? Energy that is stored and waiting to be used later

What is Gravitational Potential Energy? Potential energy due to an object’s position P.E. = mass x height x gravity

Gravitational Potential Energy PEg = mgh Measured in Joules Height is measured from an arbitrary zero level. If an egg falls from the table to the floor, then the floor is the zero level. If a person jumps from the 2nd level to the 1st level, then the 1st level is the zero.

What is Elastic Potential Energy? Potential energy due to compression or expansion of an elastic object. Notice the ball compressing and expanding

Elastic Potential Energy When an external force compresses or stretches the spring, elastic potential energy is stored in the spring. The amount of energy depends on the distance the spring is stretched or compressed. PEelastic = 1/2kx2 K = spring constant or Force Constant The spring constant will be given to you and is measured in units of N/m X= distance stretched or compressed

What is Chemical Potential Energy? Potential energy stored within the chemical bonds of an object

ASSIGNMENT Read Pages 169-170 Page 172 - Practice D - #1 and 2 Page 172 (Section Review) #’s 1- 3