 Solution

ID: past-exam-of-the-short-options-paper-shared-by-prelims-and-parts-a-and-b-of-the-physics-course-of-the-university-of-oxford/2017/s25/3/2/b/solution

At late times

C \to 1/2

and thermal equilibration requires

b_{0} C - b_{1} T = 0

. Hence

T (\infty) = b_{0} / (2 b_{1})

. Both

t ≫ k^{- 1}

and

t ≫ b_{1}^{- 1}

ensure that the exchange and thermal transients have decayed.

 New to topics? Read the docs here!