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
Related Physics GCSE answers
All answers ▸What properties makes an object stable?
Sophia (mass 47Kg) is travelling to the right with a velocity of 7.2m/s and Neesha (mass 68Kg) is travelling to the left with a velocity 4.8m/s. When they meet, they hold hands and travel off together. Give their final velocity and direction
what are the energy changes when a car rolls from the top of a hill to the bottom? Name two forces that would slow the acceleration of the car?
Why do airbags make a car safer