A stone of mass m is suspended from the free end of a wire that is wrapped around the outer rim of a pulley. The pulley is a uniform disk with mass M and radius R and turns on frictionless bearings. The pulley moves with the cord without slippage between the two. Which conservation law holds for this situation?

Aheavy boy and a lightweight girl are balanced on a massless seesaw. the boy moves backward, increasing his distance from the pivot point. what happens to the seesaw? it is impossible to predict without knowing additional information. the side the boy is sitting on will tilt downward. the side the girl is sitting on will tilt downward. nothing; the seesaw will remain balanced.