Question

If there were no air resistance, a penny dropped from the top of a skyscraper would reach the ground 9.3 s later. To the nearest integer, what would the penny's speed in m/s be right as it reaches the ground if it was dropped from rest?

Answer 1

To the nearest integer, the penny's speed in m/s be right as it reaches the ground if it was dropped from rest = 91 m/s

Explanation:

We have equation of motion

S = ut + 0.5at²

Here u = 0, a = g and t = 9.3 s

We have equation of motion v = u +at

Substituting

v = u +at

v = 0 + 9.8 x 9.3 = 91.14 m/s

To the nearest integer, the penny's speed in m/s be right as it reaches the ground if it was dropped from rest = 91 m/s