A gas undergoes a process from state $1,$ where $p_1=60,v_1=6\mathrm{.}0f\frac{t^3}{l}b,$ to state $2$

where $p_2=20,$ according to $p{v}^{1\mathrm{.}3}=$ constant. The relationship between pressure,

specific volume, and internal energy is

$u=0\mathrm{.}2651pv-95\mathrm{.}436$

where $p$ is in psi, $v$ is in $f\frac{t^3}{l}b,$ and $u$ is in Btu$/$lb$.$ The mass of gas is $10$ lb $.$ Neglecting

kinetic and potential energy effects, determine the heat transfer, in Btu. Ans: $283\mathrm{.}6$ Btu