# Sand drops fall vertically at the rate of 3 kg/s on the conveyor belt moving horizontally with a speed of 0.25 m/s .the extra power required to keep it moving?

$V \frac{\mathrm{dm}}{\mathrm{dt}}$
I.e $\left(0.25 \cdot 3\right)$N or 0.75 N
So,this amount of force will be required per second to help per meter movement of the belt,hence extra power that would be required is $P = F \cdot v = \left(0.75 \cdot 0.25\right)$ or 0.18 watt