A gas expands adiabatically: PV1.4=KPV^{1.4} = KPV1.4=K. If VVV doubles, what happens to PPP?
PPP becomes P⋅2−1.4P \cdot 2^{-1.4}P⋅2−1.4
PPP becomes P⋅21.4P \cdot 2^{1.4}P⋅21.4
PPP becomes P/2P/2P/2
PPP remains same