An ideal gas whose adiabatic exponent equals \(\gamma\) is expanded according to the law \(p=\alpha V,\) where \(\alpha\) is a constant. The initial volume of the gas is equal to \(V_{0}\). As a result of expansion the volume increases \(\eta\) times. Find: (a) the increment of the internal energy of the gas; (b) the work performed by the gas; (c) the molar heat capacity of the gas in the process.