using the definition of the specific heat at constant volume c du dt to replace du in the first law ∞Q=mCpd7 0=mCat The technical work done W1=|wc=v(p1-P2)using the definition of the specific heat at constant volume to replace dU in the first law. The technical work done Q = mCV dT  = 2 1 T T Q m CV dT  = − = − 2 1 ( ) 1 2 p p wt vdp v p p