Question$3.$ A gas describable by this equation if state, that is $P=R\frac{T}{V-b},$ confined in a piston$-$cylinder

assembly, undergoes an isothermal expansion from an initial volume $V_1$ to a final volume $V_2.$

a$)$ Evaluate the work done

b$)$ Is the work on the system or the surroundings? Justify your answer using the equation you

develop in part a$.$