A grindstone is initially rotating freely at and is then brought to a stop with constant angular acceleration in 8s. How many revolutions did the stone make in this time interval?

State one advantage and one disadvantage of using a plane mirrior as a driving mirrior

The energy equivalent of the rest mass of an electron is

Complete these sentences. if a roller coaster train has a potential energy of 1,500 j and a kinetic energy of 500 j as it starts to travel downhill, its total energy isj. once the roller coaster train gets closer to the bottom of the hill, its kinetic energy increases to 1,100 j, and its potential energy decreases to j. when the train reaches the bottom of the track and is traveling along the ground, its kinetic energy isj.