I was in class today and we flew through the relantionship with Kinetic engery and Potential engery rather quickly. I looked it up in the book but it went over my head. Ei = Ef Meaning Ei = Ef ^ ^ Kinetic intital + Potential intital = Kinetic Final + Potential Final This relates to the following question: A ball is dropped from a hieght of 60meters. How high above the ground will it be when one-third of its total engery is KE? Can you tell me the the Ei = Ef means and then give me a starting point to work the problem?