(Solved): A gas undergoes a process in a piston-cylinder assembly during which the pressure-specific volume ...

A gas undergoes a process in a piston-cylinder assembly during which the pressure-specific volume relation is $$p{v}^{1.1}=constant$$. The mass of the gas is $$0.4\mathrm{lb}$$ and the following data are known: $$p_1=160\mathrm{lbf}/{\mathrm{in}}^2,V_1=1{\mathrm{ft}}^3$$, and $$p_2=300\mathrm{lbf}/$$ in. $${}^2$$ During the process, heat transfer from the gas is $$2.1$$ Btu. Kinetic and potential energy effects are negligible. Determine the change in specific internal energy of the gas, in Btu/Ib. $$?\mathrm{u}=$$