Sand from a stationary hopper falls on a moving conveyor belt atthe rate of 4.60 kg/s as in fig. P9.72. The conveyor belt issupported be frictionless rollers and moves at a constant speed ofv = 0.820 m/s under the action of a consant horizontal externalforce Fext supplied by the motor that drives the belt.
(a) Find the sand's rate of change of momentum in thehortizontal direction. N
(B) Find the force of friction exerted by the belt on the sand.N
(c) find the external force Fext. N
(d) Find the work done by Fext in 1 second. J
(e) Find the kinetic energy acquired by the falling sand eachsecond due to the change in its hortizontal motion. J
(f) Why are the answers to parts (d) and (e) different?
