Question

Tory experiments with pulleys in physics class. She applies 60 newtons of force to a single pulley to lift a bowling ball. By adding another pulley, she'd get a mechanical advantage of 2. Whats the minimum input force she'll need to lift the ball if she adds another pulley?

Answer 1

Given,

The force applied by Tory, F=60 N

Mechanical advantage after adding the second pulley, MA=2

As Tory applies 60 N of force when there is only one pulley, the weight of the ball is 60 N.

Thus the output force is 60 N.

The mechanical advantage is given by,

On substituting the known values,

Thus the minimum input force tory need to apply is 30 N