Question

An object with a mass of `2 kg` is hanging from an axle with a radius of `2 cm`. If the wheel attached to the axle has a radius of `8 cm`, how much work would it take to turn the wheel a length equal to the circumference of the axle?

Answer 1

The work `=2.46J`

Explanation:

The load is `L=2gN`

The radius of the axle is `r=0.02m`

The radius of the wheel is `R=0.08m`

The effort is `=FN`

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

Taking moments about the center of the axle

`F*0.08=2g*0.02`

`F=(2g*0.02)/0.08=4.9N`

The force is `F=4.9N`

The distance is `d=2piR=2pi*0.08=0.16pim`

The work done is

`W=F*d=4.9*0.16pi=2.46J`