Frequency of Black body radiation HELP

re496210

If a black body is heated to a temperature T (in degrees K), the most intense radiation is at a wavelength lambda (in m), where λ·T = 2.9×10−3m*K. If the burner on your electric stove is at a temperature of 683K (really hot and glowing), find the wavelength of the most intense black body radiation emitted by it.

The wavelength is 4.25×10-6 m.

What is the frequency of the most intense black body radiation emitted by the burner in the problem above?

(I do not know how to find the frequency of the most intense black body radiation emitted)

gneill

You've found the wavelength, now what's the relationship between wavelength and frequency? Hint: what's the speed of the waves?

re496210

Thank you. I figured out that it is 7.07x10^13 Hz

phyzguy

The peak wavelength and peak frequency are not simply related by lambda*nu = c. Try reading this:

http://en.wikipedia.org/wiki/Wien%27s_displacement_law

gneill

Good catch, phyzguy. I had overlooked the variations of Planck's law with respect to wavelength, frequency, and wavenumber.

I wonder what level course this question is taken from? It's presented in a way that I would associate with introductory level, but the wavelength vs frequency subtlety for Planck/Wien I would peg at a more advanced level.