Question

a rod of length 2m and mass 0.5kg is fixed at one end and allowed to hang vertically from a rigid support. The work done in raising the other end of rod until it makes an angle of 60° with the vertical is

Answer 1

Since, if this is rotational setting where the factor of gravity works in the downward direction and support resists upward. For this reason, we have a torque of this scale:

Torque=(mh/2)g cos(60)

 The work done in this case is calculated by integrating tangential force along the arc from 60 degrees to vertical.