1 kg of air at 3.5 bar and occupying \(0.35 \mathrm{~m}^{3}\) is heated at constant volume until its temperature has rises to \(316^{\circ} \mathrm{C}\). Find \((a)\) heat added, and \((b)\) gain in internal energy per \(\mathrm{kg}\) of air.Take \(c_{v}=0.718 \mathrm{~kJ} / \mathrm{kg}\). K.