\(T_{i}=100^{\circ} C \)
\(T _{ f }=300^{\circ} C\)
\(\Delta T =300-100\)
\(\Delta T =200^{\circ} C\)
\(P = kV ^{3}\)
now \(PV = nRT\)
\(\therefore kV ^{4}= nRT\)
now \(4 kV ^{3} dV = nRdT\)
\(\therefore PdV = nRdT / 4\)
\(\therefore\) Work \(=\int PdV =\int \frac{ nRdT }{4}=\frac{ nR }{4} \Delta T\)
\(=\frac{200}{4} \times nR =50 nR\)