A rotational model with the moment of intertia l has energy levels given as lm = 2 l(l+1) 2I ,with l=0,1,2,3, and- l

A rotational model with the moment of intertia l has energy levels given as

εlm=ħ2l(l+1)2I,with l=0,1,2,3,…and-l≤m≤l,

Where l and m are integers. is the partition function of the model

1. At low temperature, by keeping only the first two terms in , show that the heat capacity of the rotational model can be given as