The expression for I ( f ) , the Planck distribution law in terms of frequency f .

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Chapter 39, Problem 39.61P

(a)

To determine

The expression for I(f) , the Planck distribution law in terms of frequency f .

(b)

To determine

To show: the integral ∫0∞I(λ)=2π5k415c2h3T4 .

(c)

To determine

The constants in part (b) and to show that σ has the value given in Section 39.5 .

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