Solution
= Solution
For the <ideal gas>, $V=Nk_BT/P$ gives $\kappa_T=1/P$. With $C_P/C_V=5/3$, the relation in part (ii) gives
$$
\boxed{\kappa_T=\frac1P,\qquad\kappa_S=\frac3{5P}.}
$$
= Solution
For the <ideal gas>, $V=Nk_BT/P$ gives $\kappa_T=1/P$. With $C_P/C_V=5/3$, the relation in part (ii) gives
$$
\boxed{\kappa_T=\frac1P,\qquad\kappa_S=\frac3{5P}.}
$$