Question

A 500-kg elevator is raised to a height of 10 m in 10 seconds. Calculate the power of the motor.

Answer 1

Power = Work done/ Time taken

Here work is done against the gravity of the earth. So

Work done = mgh [m=weight, g=9.81m/s², h=height lifted]

=500*9.81*20

=98100 Joules

Power = 98100/10 = 9810 Watts

Answer 2

Power = 4905 W

Step-by-step explanation:

Power is defined as the rate of work done against the forces acting on the system

here we know that

mass of elevator = 500 m

is moves up against gravity by distance = 10 m

total time taken by it to move = 10 s

so work done against gravity is given as

`W = mgh`

`W = 500 * 9.81 * 10`

now power given by motor is given as

`P = (W)/(t)`

`P = (500 * 9.81* 10)/(10)`

`P = 4905 W`