Question

If a uniform rod fixed at one end hangs in earth gravitational field is given an initial angular velocity w. Find how far it rotates, \(\theta\).

Picture below:

Answer 1

Assuming the rod has length L and uniform mass M.

Answer 2

Gravity is pushing down on it, but the torque is different at every point I guess.

Answer 3

What principle do you think is at work here?

Answer 4

First I suppose we can find the torque at any angle.