Answer:2000j
Step-by-step explanation:
Law of conservation of energy energy State that in a close system energy can neither be created nor destroy but can be transformed from one form to another.
At the top of the height, the rock possessed only potential energy
PE=mass×g×height
PE =8×10×25
PE=2000j
The kinetic energy at the bottom of the building will also be 2000j since energy cannot be created or destroyed,and potential energy of 2000j have been converted to kinetic energy at the bottom of the building