A construction worker on the new city hall wonders why the elevator has a counterbalance. Does a counterbalance affect the power needed to operate the elevator?
What is known:
elevator mass me = 1000 kg
elevator load mc = 1000 kg
motor efficiency e = 0.8
elevator speed ve = 1 m/s
Assume that the elevator moves with constant velocity and all transient accelerations can be ignored.
What power (kilowatts) must the elevator motor produce to lift the elevator with
an 800 kg counterweight?
Power is simply work per time, or
P = ΔU/Δt
For computations, use
P = F·v
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