Answer:
Step-by-step explanation:
ME = GPE + KE
At the top of building all the mechanical energy is GPE because the ball isn't moving yet. Just before it hits the ground, all the mechanical energy is KE because the GPE has decreased to 0 (h = 0 at ground level).
a. Total E (top of bldg.) = mgh = (5 kg)(9.8 m/s²)(22 m) = 1078 J
b. Total E (at ground) = 1/2mv² = 1/2(5 kg)(18 m/s)² = 810 m/s
c. The energies are not the same because some of the energy is converted to thermal energy as they ball falls due to friction.