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

10720 Views

See similar Physics GCSE tutors

Related Physics GCSE answers

All answers ▸

Ann and Bob play on a uniform seesaw. The seesaw is 4m long and Ann and Bob weigh 600N and 800N respectively. If both Ann and Bob start at one end of the seesaw and Bob starts to walk up the seesaw at 2m/s, after how long will the seesaw turn?


A transformer has an input voltage of 4V, an output voltage of 8V and 50 turns on its primary coil. Assuming 100% efficiency, find the number of turns on the secondary coil.


A 2 kW electric fire is switched on for 30 minutes. How many Units of electricity does it use?


A skydiver is at a height of 10,000 m. Assuming no air resistance, how fast is the skydiver travelling at 9,990 m above the ground?


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:

© 2025 by IXL Learning