Sand is deposited at a uniform rate of 20g/s and with negligible kinetic energy unto an empty convegor belt moving horizontally at a constant speed of 10m/s. Calculate the power required to maintain the constant velocity?

1 Answer
Mar 1, 2018

#2 W#

Explanation:

From Newton's 2nd Law of motion,

Force is defined as rate of change in momentum,

i,e #F=(dP)/(dt) = (d(mv))/(dt) = m (dv)/(dt) + v (dm)/(dt)# (as momentum #P=mv#)

But,see here, #(dm)/(dt)# is not equals zero,rather #(dv)/(dt)=0# as the belt is moving with constant velocity.

so,here,required amount of force(#F#) to maintain the constant velocity is #v (dm)/(dt) = 10 *(20/1000) = 0.2 N#

So,power required to be supplied to keep on the belt moving with constant speed is #F*v=0.2*10=2 W#