Question

An object with a mass of `3 kg` is hanging from an axle with a radius of `3 cm`. If the wheel attached to the axle has a radius of `28 cm`, how much work would it take to turn the wheel a length equal to the circumference of the axle?

Answer 1

The work is `=5.54J`

Explanation:

The load is `L=3gN`

The radius of the axle is `r=0.03m`

The radius of the wheel is `R=0.28m`

The effort is `=FN`

The acceleration due to gravity is `g=9.8ms^-2`

Taking moments about the center of the axle

`F*0.28=3g*0.03`

`F=3g*0.03/0.28=3.15N`

The force is `F=3.15N`

The distance is `d=2piR=2pixx0.28=(0.56pi)m`

The work is

`W=Fxxd=3.15*0.56pi=5.54J`