The potential energy is mgh. The kinetic energy is (1/2)mv^2. Total mechanical energy means the sum of those. The velocity is 0 since its just hanging.
A 0.100-kilogram apple falls from a height of 1.50 meters to 1.00 meters. Ignoring frictional effects, what is the kinetic energy of the apple at this height? Its equal to the change in PE from 1.5 meters to 1.0 meters. PE = mgh.
