When work is done on an object, energy is transferred. Power is the amount of work done in one second. Efficiency is a measure of how much useful energy is converted.
Part of Physics (Single Science)Energy
An electric motor is used to raise a load of 85 N.
The load is lifted through 3 m in a time of 9.5 s.
Calculate the work done by the motor.
Work done W = Fd
F = 85 N
d = 3 m
W = 85 N x 3 m
W = 255 J
The work done by the motor is 255 J.
Calculate the power of the motor.
power = \(\frac{\text{work done}}{\text{time taken}}\)
work done = 255 J
time taken = 9.5 s
\(\text {power} = {255 J}\div{9.5 s}\)
power = 26.8 W
The power of the motor is 26.8 W.