Question

A pulley system has a mechanical advantage of 3, and an object weighing 9 Newtons must be lifted 15 meters. How much force must be applied to lift the object?
Use the following equation to find the answer:

MA=Fo/Fi

(1 point)
Responses

1.7 N
1.7 N

27 N
27 N

0.3 N
0.3 N

3 N

Answer 1

MA = Fo / Fi, so Fi = Fo / MA = 9 N / 3 = 3 N.

(For consistency: you'd pull the rope 3 × 15 m = 45 m, so input work = 3 N × 45 m = 135 J = output work 9 N × 15 m.)