How much work does an elevator motor do to lift a 1000 kg elevator a height of 100 m?

Part A

Basic formula (you should memorize and understand)
Work = Force * distance (very simple)
force = mass * acceleration

so… Work = mad (mass * acceleration * distance)

the only thing that wasn’t told in the problem is the acceleration which is another thing you really need to memorize.
Acceleration of gravity = 9.8 m/s²

put it all together
Work = 1000 kg * 9.8 m/s² * 100 m = 980,000 kg m²/s² or 980 kJoules

Now… power = energy / time … or… power = work / time
Power = 980 kJ / 50 s = 19.6 kW

.

Elevator Motor

m=1000kg
h=100

Work Done,W by Elevator = (PE) = mgh = 1000 x 9.81 x 100

Power, P = Work Done per unit time
Since motor must lift elevator in 50s, the minimum power that the motor must supply = 1000 x 9.81 x 100 / 50 = P