I have a uniform rod of length 0.5m and mass 0.1kg, and on this rod are two balls of mass 0.03kg both at a distance of 9.997cm away from the center of the rod. There is a pin about the center of the rod upon which it rotates. The angular velocity I have worked out to be 20rad/s and the tangential velocity of the beads are 1.679m/s. The balls are released and move to the end of the rod and I want to find the work done by the pin dur to friction. I know the final kinetic energy is 0.1566J so I thought about using the work kinetic energy theorem but the result is not correct. Maybe I have been calculating the initial energies incorrectly. I took 1/2Iw^2 + 2(1/2)(Mass of ball)(Tangetial Velocity)^2 and used that. Is this the correct method?