A cloud mass moving across the ocean at an altitude of 2000 m encounters a coastal mountain range. As it rises to a height of 3500 m to pass over the mountains, it undergoes an adiabatic expansion. The pressure at 2000 m and 3500 m is 0.80 and 0.60 atm, respectively. If the initial temperature of the cloud mass is 290 K. Assume that $C_P,m$ for air is $29.88J{K}^{-1}mo{l}^{-1}$ and that air obeys the ideal gas law 

$\left(R=8.3J{K}^{-1}mo{l}^{-1},\log 2=0.30,\log 3=0.48,30\times \log 0.92=-1.086,\log {\left(\frac{4}{3}\right)}^{0.277}=0.0345\right)$

$\log \left(290\right)=2.462$