Question

Two electric motors drive two elevators of equal mass in a three-story building 10 meters tall. Each elevator has a mass of 1,000 kg.

The second elevator takes 10 seconds to do this work.

Calculate the power output of the second motor.

9.8 x 102 W
9.8 x 103 W
9.8 x 104 W
9.8 x 105 W

Answer 1

9.8 \times 10^3 W

Step-by-step explanation:

Answer 2

The power output of second motor is 9.8
`*` 10^3 W.

Step-by-step explanation:

Power is defined as the rate of doing electric work. I short it can be viewed as

Power = work done / time

Work done is the product of mass, gravity, and height. (i.e. mgh)

Given that m = 1000 kg, h = 10 m, g = 9.8 m / s^2, t = 10 s

Power = work done / time

= (m
`*` g
`*` h) / time

= (1000
`*` 9.8
`*` 10) / 10

power = 9800 W = 9.8
`*` 10^3 W.