## Energy Conservation

When we had only linear KE or translational KE of

KE = (

^{1}/_{2}) m v^{2}we found

Energy Conservationto be very useful, writingE

_{i}= E_{f}where E is the

total energy,E = KE + PE

the sum of the Kinetic Energy and the Potential Energy.

Now we have an additional form of Kinetic Energy, KE

_{rot}. Now thetotal energymust include that as well,E = KE

_{rot}+ KE_{trns}+ PEEnergy is still conserved, so when we write

E

_{i}= E_{f}we are really writing

KE

_{rot,i}+ KE_{trns,i }+ PE_{i}= KE_{rot,f}+ KE_{trns,f}+ PE_{f}where we have now written KE

_{trns}to explicitly state "translational KE" orKE

_{trns}= (^{1}/_{2}) m v^{2}As before, energy changes from one form to another but the

total energyremains constant.(c) 2005, Doug Davis; all rights reserved

Rotational KESummaryReturn to ToC, Rotational Kinematics