Given : Rev. adiabatic expansion(q=0) , Vf =8 Vi , gamma= 1.33 , n = 1 , T= 300K
using TVγ-1 = constant
T1 / T2 = (V2 / V1 ) ^ (γ-1)
300/ T2 = 8 ^ ( 1.33-1)
T2 = 150 K
Now, using γ = Cp / Cv
1.33 = 4R / 3R = Cp /Cv
So, by compairing both sides we can say that : Cv = 3R
Using : ΔU= q +w
As, q=0 ; ΔU= w
w = nCvΔT
w= 1 (3R) ( T2 -T1 )
w= 3R ( 150-300 )
w= -150R