Solve the all parts of given question:
Question: Ann throws a rock upward with an initial speed of 29.4 m/s from the top of a 60-meter tower. If a = 9.80 for the acceleration due to gravity and air resistance is ignored,
Part A: What is the rock's velocity the instant it hits the ground at the base of the tower? (Hint: answer is not zero, choose the upward direction as positive)
Show how you get the answer, so that I can better understand how to do it.