Question

 Using the classical theory, derive the formula ρ(ν)dν = 8πν2 c 3 kBT dν for the blackbody radiation where ρ(ν) is the energy per unit of volume in the frequency interval ν to ν + dν of the blackbody spectrum of a cavity at temperature T.

Answer 1

Answer

The formula is given by

$ρ(ν)dν =\frac{ 8πν^2 }{c^ 3 k_BT }dν$

Where

$v=c/\lambda$

ρ(ν) is the energy per unit of volume in the frequency interval ν to ν + dν of the blackbody spectrum of a cavity at temperature T