For monoatomic gas degree of freedom f=3 and γ=‌
5
3
Here for gas, Initial pressure (P1)=75‌kPa Initial volume (V1)=1200cm3 Final volume (V2)=150cm3 Final pressure (P2)= ? For adiabatic process, P1V1γ=P2V2γ ⇒75×(1200)γ=P2(150)γ ⇒P2=75×(‌
1200
150
)‌
5
3
=75×(8)‌
5
3
=75×32‌kPa =2400‌kPa Work done in adiabatic process, W=‌