posted by sam on .
A crane lifts a concrete hopper of mass 370 kg from the ground to the top of a 38 m building that is under construction. The hopper moves with a constant speed during the lift. The power rating of the crane motor is 8.2 kiloWatts.
How much work does the crane do in lifting the hopper to the top of building?
You don't need the power rating of the motor to calculate the work required to lift one.
It is W = M g H
H = 38 m
g = 9.8 m/s^2
M = 370 kg
The answer will be in joules