Question

A pulley system has an MA of 4. How much force would be necessary to pull a 200 newton box

Answer 1

Mechanical advantage is defined as

$MA = \frac{F_{output}}{F_{input}}$

MA = 4

now we will have

$F_{output} = 200 N$

as we need to pull up a box of weight 200 N

now by above formula we can find how much force it requires to pull up the box

$4 = \frac{F_{output}}{F_{input}}$

$4 = \frac{200}{F_{input}}$

$F_{input} = \frac{200}{4} = 50 N$

so it requires 50 N force to pull the weight of 200 N