A particle of mass m is attached to an inextensible massless string, and moves on the horizontal surface of a frictionless tabletop. The other end of the string passes through a hole in the tabletop, and is held taut by me. Initially the particle is moving in a circle with radius r0 and angular speed !0. I start to pull the string through the hole at a steady rate. Answer the following questions: a) Of kinetic energy and angular momentum, which one is conserved and which one is not? Explain how the tension force on the particle acts to change one but not the other
