In the graph below, each unit on the horizontal axis is $\backslash (1\mathrm{.}90\backslash$times $10^\{-3\}\backslash$mathrm$\{$~m$\}^\{3\}\backslash )$ and each unit on the vertical axis is $0\mathrm{.}4$ atm.

$($a$)$ Determine the change in internal energy of the gas if $2002$ J of heat is added as it expands in volume along the direct path CA$.$ J

$($b$)$ To get the same change in internal energy, how much heat must be added to the gas as it goes along the path CBA? J