Question

An object with a mass of `3 kg` is hanging from an axle with a radius of `2 cm`. If the wheel attached to the axle has a radius of `5 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 `=3.69J`

Explanation:

The load is `L=3gN`

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

The radius of the wheel is `R=0.05m`

The effort is `=FN`

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

Taking moments about the center of the axle

`F*0.05=3g*0.02`

`F=3g*0.02/0.05=11.76N`

The force is `F=11.76N`

The distance is `d=2piR=2*pi*0.05=(0.1pi)m`

The work is `W=Fxxd=11.76xx0.1pi=3.69J`