1. The problem statement, all variables and given/known data A pendulum is swinging inside a lift. What happens to the bob if the lift cable breaks when the bob is at the lowest point? 2. Relevant equations 3. The attempt at a solution When I consider the bob relative to the lift, the bob is apparently weightless. There should be no net force acting on the bob as observed by the person in the lift. However, the answer state that there will be a uniform circular motion relative to the falling lift. Where does the centripetal force come from??