Question

An object with a mass of `8 kg` is hanging from an axle with a radius of `5 cm`. If the wheel attached to the axle has a radius of `45 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 `=2.74J`

Explanation:

The load `L=(8g)N`

Radius of axle `r=0.05m`

Radius of wheel `R=0.45m`

Taking moments about the center of the axle

`F*R=L*r`

`F*0.45=8*g*0.05`

`F=(8*g*0.05)/0.45=8.71N`

The force is `F=8.71N`

The distance is `d=2pir=2pi*0.05=0.1pim`

The work is

`W=Fd=8.71*0.1*pi=2.74J`