A 5.5 kg bowling ball initially at rest is dropped from the top of a 12 m building. It hits the ground 1.75 s later. Find the net external force on the falling ball.

We are given that:

m = 5.5 kg

d = 12 m

t = 1.75 s

Using the distance formula, we can get the acceleration of the ball:

d = (1/2) a*t^2

Rearranging:

a = 2d/t^2 = 2 * (12 m) / (1.75 s) ^2

a = 7.837 m/s^2

Using Newton’s 2nd law, force is defines as:

F = ma

F = 5.5 kg (7.837 m/s^2)

F = 43.10 N