Unit 8(Chapter 10 & 11)

Potential Energy

Energy• Energy is defined as the

ability to do work– 6 Types of energy

• Kinetic Energy: associated with motion

• Heat: associated with the speed of internal particles

• Chemical: bonds atoms together• Electromagnetic: moving electric

charges• Nuclear: in the atomic nucleus• Potential Energy: energy of position

(energy at rest)

Energy

• The units of energy are joules• joules are also the same unit as work!

(How Confusing!)

• You can think of energy as stored work – that is ready to be released!

• Energy cannot be created or destroyed – only changed from one type of energy to another!

Potential Energy

• Is energy stored in an object due to its position

• Potential Energy is also considered energy at rest

• GPE = mass x acceleration due to gravity x height

Potential Energy

Potential Energy (joules)

mm - - mass of object in kggg - - acceleration of gravity in m/s2

hh - - height of object, in mGPEGPE – – gravitational potential energy in J

GPE = mgh

Potential Energy

• Gravitational potential energy depends on an objects mass and height

• Objects with potential energy don’t use their energy until they start moving.

• The further the object is from the ground the more potential energy it has

• Chemical potential energy is energy stored in the form of chemical bonds.

Law of Conservation of Energy

• Energy can never be created or destroyed just turned into another form.

Law of Conservation of Energy

• When a ball flies through the air it does not lose energy even though it slows down and speeds up

• The energy in the ball changes from kinetic to potential and then back to kinetic energy