posted by Fonda on .
A 1 kg object requires 10 N of force to lift it 5 m from the bottom of a well. (use g = 10 m/s2). The object is then dropped. What is the total energy when the object has fallen halfway down the well (2.5m)?
That depends upon where you define the level of zero potential energy to be. If it is the bottom of the well, the object has 50 J of potential energy when lifted 5 meters from the bottom.
While it falls, it retains that total energy. Half of it will be kinetic energy halfway down.