Question

Written:
1) An 8.5 x 102 kg elevator is pulled up at a constant velocity of 1.00 m/s by a motor
that consumes 10.0 kW of power. Calculate the efficiency of the motor.

Answer 1

Answer:

0.833

Explanation:

Power = energy / time

Power = force × distance / time

Power = force × velocity

P = (850 kg) (9.8 m/s²) (1.00 m/s)

P = 8330 W

P = 8.33 kW

The efficiency of the motor is therefore:

e = 8.33 kW / 10.0 kW

e = 0.833