Question

An electric motor does 900j of work for 8 hours. Calculate the power used​

Answer 1

Answer:

0.031 W

Explanation:

The power used is equal to the rate of work done:

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

where

P is the power

W is the work done

t is the time taken to do the work W

In this problem, we have:

W = 900 J is the work done by the motor

t = 8 h is the time taken

We have to convert the time into SI units; keeping in mind that

1 hour = 3600 s

We have

$t=8\cdot 3600 =28,800 s$

And therefore, the power used is

$W=\frac{900}{28800}=0.031 W$