# An object with a mass of 4 kg is hanging from an axle with a radius of 15 m. If the wheel attached to the axle has a radius of 18 m, how much force is needed to raise the object?

May 5, 2017

The force is $= 32.7 N$

#### Explanation:

Radius of axle $r = 15 m$

Radius of wheel $R = 18 m$

Taking moments about the center of the axle

$F \cdot R = L \cdot r$

$F \cdot 18 = 4 \cdot g \cdot 15$

$F = \frac{4 \cdot g \cdot 15}{18} = 32.7 N$