5) A metal ball of mass m with a hole through it is threaded in a frictionless vertical rod. A massless string of length / is attached to the ball and runs over a massless, frictionless pulley to support a block of mass M. Show that the potential energy can be U(h) = Mg√√/h² + b² − mgh a) written as b) Can the system be in stable equilibrium? h m b d H M

5) A metal ball of mass m with a hole through it is threaded in a frictionless vertical rod. A massless string of length / is attached to the ball and runs over a massless, frictionless pulley to support a block of mass M. Show that the potential energy can be U(h) = Mg√√/h² + b² − mgh a) written as b) Can the system be in stable equilibrium? h m b d H M