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Prof.Grace
Sand drops at the rate of 2000 kg/min. from the bottom of a hopper onto a belt conveyor moving horizontally at 250 m/min. Determine the force needed to drive the conveyor, neglecting friction.
Newton's 2nd law of motion :- F + u.dm/dt = m.dv/dt [ for variable mass systems : u is velocity wrt incoming mass, u.dm/dt is thrust ] You can substitute the values.