A 350 Kg Block Is Pulled Along a Moving Conveyor Belt

Multiple Choice

A 3.50 kg block is pulled along a moving conveyor belt at a constant speed of 0.500 m/s relative to a stationary observer while the belt moves at a constant speed of 0.200 m/s in the opposite direction. If the coefficient of kinetic friction is 0.400, the magnitude of the mechanical energy dissipated, in J, caused by the force of friction on the block in 8.00 s is

A) 5.6.
B) 22.0.
C) 32.9.
D) 54.8.
E) 76.8.