A puck is moving in a circle of radius r with a constant speed  V0 on a level frictionless table. A string is attached to the puck which holds it in the circle. The string passes through a frictionless hole and is attached on the other end to a hanging object of mass M. The puck is now made to move with a speed v=3v0 but still in circle. The mass of the hanging object is left unchanged. The acceleration a of the puck and the radius r of the circle are now given by (a0 is the initial acceleration of the puck)