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2 identical objects are placed in a room at 21 ∘C. Object 1 has a temperature of 90 ∘C and object 2 has a temperature of 29 ∘C.?
What is the ratio of the net power emitted by object 1 to that radiated by object 2?
Express your answer using two significant figures.
2 Answers
- ?Lv 72 years ago
The ratio will be = (273+90-21)^4/(273+29-21)=1.2^4=2.19 times.
Use the black body formula of power radiation which is Stefan's constant*T^4
- az_lenderLv 72 years ago
Net power emitted by either one will be
(surface area)*(sigma)*[T^4 - (294.15K)^4].
So the ratio is
[363.15^4 - 294.15^4] / [302.15^4 - 294.15^4].
I suspect the 2nd term in each binomial hardly matters at all (!) but I'll include them anyway. The ratio is
(9.905 billion)/(0.848 billion) = 12
