# An object with a mass of 15 kg is hanging from an axle with a radius of 30 m. If the wheel attached to the axle has a radius of 9 m, how much force must be applied to the wheel to keep the object from falling?

Jan 8, 2018

The force is $= 490 N$

#### Explanation:

The load is $L = 15 g N$

The radius of the axle is $r = 30 m$

The radius of the wheel is $R = 9 m$

The effort is $= F N$

The acceleration due to gravity is $g = 9.8 m {s}^{-} 2$

Taking moments about the center of the axle

$F \cdot 9 = 15 g \cdot 30$

$F = \frac{15 g \cdot 30}{9} = 490 N$

The force is $F = 490 N$