Question

how long in seconds would it take a rock to fall 450 feet and what would be the final velocity of the rock in miles per hour when it hit the ground

Answer 1

Answer:

S = Vy t + 1/2 g t^2 = 1/2 g t^2    vertical speed with zero initial speed

t = (2 S / g)^1/2      with g = 32 ft/sec^2

t = (900 / 32)^1/2 = 5.30 sec    time to reach ground

V = a t = 32 ft/s^2 * 5.30 s = 170 ft/sec

170 ft/sec / (88 ft/sec / 60 mph) = 116 mph           since 88 ft/sec = 60 mph