Potential and Kinetic 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 Don’t look down, Rover! Good boy!

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

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

What is Kinetic Energy? Energy an object has due to its motion K.E. = .5(mass x speed2) KE = 1/2mv2 M = mass (kg) V = velocity (m/s) Unit: Joule (J)

If an object changes speed then the KE also changes If the velocity changes then a force must have been applied over a distance Therefore: work is done on an object to change that object speed. W = DKE Fd = ½ m(vf2 - vi2)

Bill Nye http://www.youtube.com/watch?v=zTXW9aRO23Y http://www.youtube.com/watch?v=Vfcsq6ylRzg

Conservation of Energy Conservation of Energy – energy can not be created or destroyed but it can change forms If friction is ignored ΔPE = ΔKE If friction is not ignored ΔPE = ΔKE + heat  

OR Total energyinitial = total energyfinal   PE I + KE f = PE f + KE I + Wfriction

http://www. energyeducation. tx http://www.energyeducation.tx.gov/energy/section_1/topics/potential_and_kinetic_energy/potential__kinetic_energy.html http://www.youtube.com/watch?v=ZEajHxTM1CE http://www.youtube.com/watch?v=qZ4FFWvZtyo