Question

7 luggage of mass 10 kg each, fall on a horizontal conveyor belt in an airport moving at 2 m/s in every 5 seconds. Power of motor operating the belt is __.

• A.
  56 watt
• B.
  70 watt
• C.
  112 watt
• D.
  140 watt

Answer 1

The correct option is A

56 watt
Power = Force $\times$ Velocity
Change in momentum in 5 seconds is $\Delta$P.
Force, F = <!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> $\frac{\Delta P}{\Delta t}$ = $\frac{7\times 10\times 2}{5}$
P = $\frac{7\times 10\times 2\times 2}{5}$ = 56 watt