A 27kg child jumps to the ground from the top of a fence tha

A 27-kg child jumps to the ground from the top of a fence that is 2.0 m high. You analyze the problem using upward as the positive x direction. Taking x = 0 to be at the bottom of the fence, what are the initial potential energy of the child-Earth system and the change in the system kinetic energy during the jump? Enter your answers numerically separated by a comma. Repeat the previous part for x = 0 at the top of the fence. Enter your answers numerically separated by a comma.

Solution

part (A) is correct

part(B) -> initial potential energy = mgx = mg X(0) =0

final potential energy = mgx = mg (-2) = -530 J

change = in system KE = 530

so answer will be (0,530)