What does a photovoltaic cell do?

converts electricity into heat for pools

uses pumps and the sun’s energy to heat buildings

collects the sun’s energy for heating pools

converts the sun’s energy into electricity

Two masses are connected by a rope that hangs over a pulley as shown below. the pulley is a uniform cylinder of radius 푅=0.381meters and mass 푀=3.1푘푔. initially 푚"is on the ground and 푚#rests 2.5 meters above the ground. if the system is released, use conservation of energy to determine the speed of 푚#just before it strikes the ground. assume the pulley bearing is frictionless.