The discussion revolves around the rate of electromagnetic (EM) emission based on the surface characteristics of materials, specifically comparing a black painted surface and an aluminum plate. The subject area includes concepts of emissivity, black body radiation, and thermal dynamics.
The discussion is active, with participants providing insights and questioning assumptions about the heating conditions and the effects of emissivity on EM emission. Some guidance is offered regarding the application of Stefan-Boltzmann's law, but no consensus has been reached on the conclusions drawn from the discussion.
Participants note that no other variables were stated in the original question, leading to assumptions about the conditions under which the surfaces are compared. There is an acknowledgment of the need for differential heating to maintain temperature differences.
And, why do you think that ?druscilla said:I would think the black painted surface is
Right, but the aluminium plate is hotter. So the question is, is the temperature difference enough to overcome the emissivity difference? How will you assess that?druscilla said:Since dark matt surfaces are better emitters of em radiation because of higher emissivity
I think we are supposed to assume those temperatures are maintained somehow.hutchphd said:Also how are these objects being heated? They will not maintain a temperature difference unless differentially heated.
I see no reason to jump to the opposite conclusion.druscilla said:No other variables were stated in the question, so now I think the Al plate must be the answer given Stephan-Boltzmann's law