An object with a mass of 7 kg is hanging from an axle with a radius of 36 m. If the wheel attached to the axle has a radius of 9 m, how much force must be applied to the wheel to keep the object from falling?

1 Answer
Feb 22, 2016

This is a similar case to a lever: the torque on both sides need to be the same for balance. τ1=rF=rmg=3679.8=2469.6 Nm. τ2=rFF=τ2r but τ1=τ2 so F=2469.69=274.4 N.

Explanation:

I think the explanation above is clear, but it's worth pointing out that the force acting one the 7 kg mass is its weight force, F=mg where g is the acceleration due to gravity, 9.8 ms2.