The temperature of $3.0$ kg of krypton gas is raised from $-20^{\circ} \mathrm{C}$ to $80^{\circ} \mathrm{C}$. $(a)$ If this is done at constant volume, compute the heat added, the work done, and the change in internal energy. ( $b$ ) Repeat if the heating process is at constant pressure. For the monatomic gas $\mathrm{Kr}, c_{v}=0.0357 \mathrm{cal} / \mathrm{g} \cdot{ }^{\circ} \mathrm{C}$ and $c_{p}=0.0595 \mathrm{cal} / \mathrm{g}$ ${ }^{\circ} \mathrm{C} .$