A ball of mass 0.5kg is released from rest from the edge of a cliff 25m above the ground. Ignore air resistance.
a. (i) After the ball has fallen through 15m, calculate the decrease in its gravitational potential energy.
b. (ii) Hence find the kinetic energy gained by the ball after falling 15m.
c. (iii) Determine the speed of the ball when it is 10m above the ground.
d. (iv) Using your results, verify that the total mechanical energy of the ball remains constant during its fall.