- #1

albertrichardf

- 165

- 11

Say you have a uniform rod in free-fall. Would it rotate?

Suppose you compute the rotation around the CM. I computed that the lever arm is the same on either side, regardless of the angle at which the rod falls, so there can't be any rotation. So if I just dropped a 30º to the horizontal rod, it would fall and stay at 30º to the horizontal. Is that correct?

Also, suppose I compute the rotation around one end of the rod. The torque is non-zero, but the rod is not rotating around that point. How is that possible? Furthermore, since the rod is falling, the end is falling as well, so my reference point is moving. If the reference point was stationary (the end of the rod is falling, it does not necessarily coincide with the point), does that change anything?

Thank you for answering