1. The problem statement, all variables and given/known data A ball of mass m is attached to a massless rod and is suspended from a frictionless pivot. It is moving in a vertical circle or Radius R such that it has speed v1 at the bottom. The ball is in a vacuum. Find an expression for the force exerted by the rod at the top of the loop as a function of m, v1, g, and R. This is more of a general question. Not looking for an answer to the entire problem. I'm just wondering if the rod exerts a normal force if it is massless. If so, at the top there is a Normal force acting upward and gravity and tension acting downward, correct?