Answer to Question #287554 in Physics for Jihyo

Question

A machinist is using a wrench to loosen a nut. The wrench is 25.0 cm long, and he exerts a 17.0-N force at the end of the handle at 37° with the handle. (a) What torque does the machinist exert about the center of the nut? (b) What is the maximum torque he could exert with this force, and how should the force be oriented?

Answer 1

(a) The torque is

$$\tau=Fd\sin\theta=2.26\text{ N}·\text m.$$

(b) The maximum torque is

$$\tau_\text{max}=Fd\sin90°=17·0.25·1=4.25\text{ N}·\text m.$$

The force should be applied at 90° to the handle of the wrench.