sorry, this was my question from yesturday, and now my assignment is due tomorrow. anyone have any help for me? A Leslie cube has a surface temp of 97C. One of its four side faces has an area of 100 cm^2 and is painted black. Calculate: a) the wavelength at which the spectral intensity (per unit wavelength) is a maximum b)the total intensity (all wavelengths) of the emitted radiation just outside the surface C) the total power emitted by the black surface for a) i used lambda=2.9*10^-3/T (not sure if this is the correct way of doing it) for b) i wanted to use Stefan's Law but this seems to simple for c) i multiplied the answer from b) by the area of the four sides. does any of this sound correct? i seem to be struggling on this topic also, in Planck's energy density equation, what exactly is the spectral energy density? is it also known as anything else? thanks.