Question

An object with a mass of `24 kg` is hanging from an axle with a radius of `14 m`. If the wheel attached to the axle has a radius of `42 m`, how much force must be applied to the wheel to keep the object from falling?

Answer 1

`8g N`

Explanation:

The moments must balance, so `24 xx 14 = F xx42`, where `F` is the force that must be applied. Hence `F=24 xx 14/42 = 8`. Hence `8g`, that is, the local weight of a mass of `8kg`, since one kilogram has a weight of `g` Newtons. (Informally, it would require a "weight' of 8kg on the wheel to balance the 'weight' of 24 kg on the axle.)