A wrench with a length of #40 cm# is being used to unscrew a #4 cm# bolt. If a torque of #15 Nm# is needed to overcome the friction keeping the bolt in place, what is the minimum torque that must be applied to the wrench to unscrew the bolt?
Torque (Nm) = Force (N) x distance (m) & the trick is to remember that you have to convert the distance into metres first.
I think the question should probably read 'what is the minimum force that should be applied' but still ...
The force is found from dividing the torque required (15 Nm) by the distance 0.4 m.