Chapter 8, Problem 4CQ

If you are using a rope to raise a tall mast, attaching the rope to the middle of the mast as in Figure Q8.4 a gives a very small torque about the base of the mast when the mast is at a shallow angle. You can get a larger torque by adding a pole with a pulley on top, as in Figure Q8.4 b. Draw a diagram showing all of the forces acting on the mast and explain why, for the same tension in the rope, adding this pole increases the torque on the mast.

Figure Q8.4