# Frequency of Black body radiation HELP

1. May 17, 2012

### 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)

2. May 17, 2012

### Staff: Mentor

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

3. May 17, 2012

### re496210

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

4. May 18, 2012

### phyzguy

5. May 18, 2012

### Staff: Mentor

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.