A clever inventor arranges ropes and pulleys to lift a heavy log. The log weighs 2,000 newtons. If she pulls 10 meters of rope to lift the log 2 meters, what force does she apply to the rope

Given :

A clever inventor arranges ropes and pulleys to lift a heavy log. The log weighs 2,000 newtons.

To Find :

If she pulls 10 meters of rope to lift the log 2 meters, what force does she apply to the rope.

Solution :

Mechanical advantage is :

Also, mechanical advantage is given by :

M.A = Output Force/Input Force

Input Force = Output Force/M.A

Input Force = 2000/5

Input Force = 400 N.

Therefore, she will apply 400 N to the rope.

it is called kinetic energy