\(\mathrm{TV}^{\gamma-1}=\text { constant }=\mathrm{T}_{\mathrm{f}}(2 \mathrm{~V})^{\gamma-1}\)
\(\mathrm{~T}_{\mathrm{f}}=\mathrm{T}\left(\frac{1}{2}\right)^{1 / 2}=\frac{\mathrm{T}}{\sqrt{2}}\)
\(\mathrm{~W}=\frac{\mathrm{R}\left(\frac{\mathrm{T}}{\sqrt{2}}-\mathrm{T}\right)}{1-\frac{3}{2}}=2 \mathrm{RT} \frac{(\sqrt{2}-1)}{\sqrt{2}}\)
\(=\mathrm{RT}(2-\sqrt{2})\)