Calculate the energy consumed in electrical units when a 75 W fan is used for 8 hours daily for one month (30 days).
Power, P = 75 W
Time of usage, t = 8 hour × 30 days = 240 hours
Electrical energy consumed is the product of power and time of usage.
Electrical energy = power × time of usage = P × t
A vehicle of mass 1250 kg is driven with an acceleration 0.2 ms-2 along a straight level road against an external resistive force 500 N.Calculate the power delivered by the vehicle’s engine if the velocity of the vehicle is 30 m s-1 .
The vehicle’s engine has to do work against resistive force and make vechile to move with an acceleration. Therefore, power delivered by the vehicle engine is