# A wrench with a length of 20 cm is being used to unscrew a 4/3 cm bolt. If a torque of 1 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?

I suppose that you are asking for the perpendicular force applied at the wrench extremity to get a torque of $1$[Nm]. In this case $f$ value can e extracted from the equality$f \times 0.20 = 1$. Solving for $f$ we obtain $f = 5$[N]