1. The problem statement, all variables and given/known data This is a 'random discussion' that I had today with a student; it is not out of a textbook, nor does the solution carry any weight at all (pls excuse pun). A simple pendulum is happily swinging back and forth attached to a pin in the wall of the lift, where the pin is more than the length of the pendulum, below the lift roof. Suddenly the lift cable snaps and the lift goes into free fall (ignore air resistance). 2 questions: (i) what is the subsequent motion of the pendulum as viewed by a person in the lift (ii) are there any videos that verify the (surprising) answer to (i) ? I believe that the pendulum, depending on the state when the cable snaps, either remains absolutely stationary or goes in full circles at a constant angular speed .. becoming a perfect analogue clock. 2. Relevant equations none 3. The attempt at a solution It seems to me that under free fall the bob becomes (effectively) weightless. This would seem to suggest the solution above but does that really happen? It seems surprising.