Chapter 2.2Potential Energy

Gravitational Potential Energy Mass (m) is a scalar quantity and is

measured in kilograms (kg). Doesn’t change.

Weight (W) is a vector quantity. It is a measure of the force of gravitational attraction on an object in newtons (N). Depends on acceleration due to gravity (g).

W=mg , W=weight, m=mass, g=9.81m/s2 for earth

To calculate the gravitational potential energy, use this formula…

Ep(grav)=W (work done to life object through a vertical height)

=Fd

Ep(grav)=mgh

Do practice problem Pg 174 #1,2,3

Elastic Potential Energy The energy that is stored in a stretched

or compressed spring, a trampoline, or a spring diving board. Also, in an elastic band.

Potential energy is energy that is stored and has the potential to do work

It is only useful when it is converted into some other form of energy

Chemical Potential Energy When a chemical change takes place,

the positions of electric charges are altered and energy is released.

Ex. Potential energy of fossil fuels like gasoline is only released when the gasoline undergoes a chemical combustion reactions