What was the height from which the ball was dropped?

Question

A baseball is released at rest from the top of the Washington Monument. It hits the ground after falling for 6.0 s. What was the height from which the ball was dropped? (g=9.8 m/s^2 and assume air resistance is negligible). Solve this problem using numbers and solve this problem using units.

Answer 1

Since the ball was released from rest, u, the initial velocity = 0

 

hence h = 1/2*g*t^2

 

h(m) = 1/2 * 9.8(m/s^2) * 6^2(s^2)

 

h = 176.4 m