Question

sand is falling on conveyor belt at the rate of 10kgs-1 the extra power req
hfhggguired to move the belt velocity 4m/s​

Answer 1

F= rate of change of mass × velocity change

$\implies F = 10 kg/s × 4 m/s\\\\\implies F=40\:N$

Now,

Power = work done per second

P = force * rate of displacement

$\implies P=Fv\\\implies P=(40\:N)(4\:m/s)\\\implies P=160\:W$