64 Sand is poured vertically on to a moving conveyor belt at a steady rate so that the mass of sand landing per unit time is u. The conveyor belt maintains a constant speed of v. The sand slips on the conveyor belt until it also reaches the speed v. sand V conveyor belt The minimum power required to keep the conveyor belt moving at constant speed while the sand is falling on it will be A. zero. . C. D. 2. .