Respuesta :
Answer:
The rate of increase of the energy content of the room when all the eletrical devices are on is 1650 W.
Explanation:
From conservation of energy,
Rate of energy transfer ([tex]\dfrac{dE}{dt}[/tex]) = Rate of change of energy within the room ([tex]E_{in} - E_{out}[/tex]).
As according to the problem no heat transfer occurs through the walls of the room we can assume that there is no energy transferred to the outside of the room, i.e., [tex]E_{out} = 0[/tex].
If all the electric devices are on inside the room, then the rate of increase of energy is equal to the power ([tex]P_{in}[/tex]) consumed bt the electrical devices inside the room. Therefore we can write,
[tex]\dfrac{dE}{dt} = \dfrac{dE_{in}}{dt} = P_{in} = P_{bulb} + P_{TV} + P_{refrigerator} + P_{iron} = (40 + 110 + 300 + 1200)~W = 1650~W[/tex]
