Question

a penny dropped from the deck oof the empire state building 443.18 meters from the ground. determine the time it takes the penny to free fall to the street below

Answer 1

Use s = 1/2 g t^2 (neglecting air resistance).

t = sqrt(2s/g) = sqrt(2·443.18 m / 9.81 m/s^2)
= sqrt(886.36 / 9.81) ≈ 9.5 s.

So about 9.5 seconds (idealized; with air resistance a real penny would take substantially longer — on the order of tens of seconds).