Question

the observation deck of a tall skyscraper 370 m above the street. Determine the time required for a penny to free fall

Answer 1

X = Xo + Vo*t + 0.5*g*t^2

Let's take Xo to be 0.
This means X is 370.
g = 9.8 m/s^2
The penny is at rest to begin with, so Vo = 0.

370 = 0 + 0 + 0.5*9.8*t^2
370 = 4.9*t^2
75.51 = t^2

t = 8.7 seconds