A motor does 4.8kJ of work in 2 minutes. What is its power output?

Power is the RATE of work done or energy transferred.
By the Law of Conservation of Energy, energy cannot be created or destroyed, only converted from one form to another. Power is the rate at which energy is transferred between forms, also known as the rate of work done. To calculate power, we use the following equation:
Power = Energy/Time
where Power is measured in Watts, Energy in Joules and Time in Seconds.
So, for the above question, begin by converting the units and then substitute the values into our equation:
1) 4.8kJ = 4800J
2) 2minutes = 120s
3) P = E/t so P = 4800/120 = 40W

SJ
Answered by Simran J. Physics tutor

11571 Views

See similar Physics GCSE tutors

Related Physics GCSE answers

All answers ▸

Person A, weighing 35 kg, is sitting 10m away from a seesaw pivot. Person B, weighing 50 kg, it sitting at the other end, at a distance d. Calculate d, in order for the seesaw not to topple over. (g=10m/s^2)


A jug containing 0.250 kg of liquid is put into a refrigerator. Its temperature decreased from 20°C to 15°C. The amount of energy transferred from the liquid was 5,250 J. Calculate the specific heat capacity of the liquid.


A mass of 2.5kg is raised by a height of 8m in 36 seconds using an electronic motor. Calculate the power of the motor.


A car of mass 1000 kg is travelling at 15 m/s. The driver applies the brakes for 4 seconds, slowing the car to 5 m/s. What is the average power output of the brakes over the 4 seconds? Assume there are no other forces acting on the car.


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2026 by IXL Learning