How much work does an elevator motor do to lift a 1200-kg elevator car a height of 80 m at constant speed?

The increase in gravitational potential energy of the elevator car when is lifted to a height of 80 m is given by

where m=1200 kg is the mass of the elevator car,  is the gravitational acceleration, and  is the variation of height of the elevator car. If we plug these numbers into the equation, we find:


For the work-energy theorem, the work done by the motor to lift the elevator must be equal to the energy acquired by the elevator car: but the energy acquired by the elevator car is , therefore the work done by the motor is exactly equal to this value:

Ireally don’t know

Mass and velocity are the 2 factors used to calculate kinetic energy. the equation for kinetic energy is (1/2)mv^2. hope this !