Question

Consider a room that is initially at the outdoor temperature of 20°C. The room contains a 40-W light bulb, a 110-W TV set, a 300-W refrigerator, and a 1110-W iron. Assuming no heat transfer through the walls, determine the rate of increase of the energy content of the room when all of these electric devices are on.

Answer 1

Answer:

1560 W

Explanation:

All we need to do here just balance the energy using energy conservation.

that is $E_{in}=E_{out}$

Since no energy is leaving out $E_{out}$ = 0

and  $E_{in}= E_{light}+E_{TV}+E_{refrigerator}+E_{iron}$

⇒ $E_{in}$= 40+110+300+1110= 1560W

therefore the rate of increase of energy content of the room = 1560W

when all the decives were on