A gas is compressed at constant temperature (400 K) from P=1 bar to P=5 bar. The gas is described by the following equation of state vP=RT+aP^3 With a =0.0102667 L/(atm^2mol).The constant pressure heat capacity of the ideal gas at 400K is 3.85R. a) Obtain an expression for (dU/dP)T in terms of measurable properties b) Find the change in U of the process.