Question

A 1200 W microwave oven transforms 1.8 x10^5 J of energy while reheating some food. Calculate how long the food was in the microwave. Answer in minutes.

Answer 1

2.5 min

Step-by-step explanation:

Hello

by definition the power is the amount of work done per unit of time. in this case, we know the total power and the work developed

`1 Watt= (Joule )/(sec)`

Let

`P=1200 W\\E=1.8 *10^(5)\\X=(1.8 *10^(5) j )/(1200 W)\\X= unknown\ time\ (sec) \\\\we\ need\ the\ answer\ in\ minutes,\\ 1\ min=60\ sec\\\\x=150 sec \\150\ sec*((1 min)/( 60 sec))=2.5 min\\`

hence , the data is not altered, we did it like this to eliminate the sec units.

Answer 2.5 min

I hope it helps