Net Work = Change in Kinetic Energy. What about potential energy? 1. The problem statement, all variables and given/known data When we say net work = change in kinetic energy, does that mean that if the height of an object changes (and its initial and final velocity) do not change, then the work done also equals the potential energy? Sometimes I see texts saying work = change in potential energy, but i thought it was change in kinetic energy. Do they mean change in potential energy = work done by the force(s) that change the height of the object and change in kinetic energy = NET Work done? 2. Relevant equations U = mgh KE = 1/2mv^2 Work = Change in KE OR Change in PE (?) 3. The attempt at a solution What confuses me is that if i raise a book from a height of 0 m to 5m, then the potential energy definitely changes but the kinetic energy does not change (0m/s initially and 0 m/s final). So Change in kinetic energy in this case cannot equal change in potential. So here work does NOT equal change in kinetic energy.