torques and angular rotation.... 1. The problem statement, all variables and given/known data[/b a grindstone used to sharpen tools is rotating at an angular speed of 8 rad/s when an axe is pressed against it. because of the torque produced on the grindstone by the force of friction between it and the axe, it comes to rest in four rotations. a)Find the frictional force produced, assuming the grindstone is a cylinder of mass 5kg and radius 0.4m 2. Relevant equations Ff = mu N Fc = mrw^2 3. The attempt at a solution The normal force will be equal to the centripetal force. The coefficient of friction wasn't given. How do I find that? Can someone help me please?