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

Answer:

Power = 4905 W

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

$W = mgh$

$W = 500 \times 9.81 \times 10$

now power given by motor is given as

$P = \frac{W}{t}$

$P = \frac{500 \times 9.81\times 10}{10}$

$P = 4905 W$