\sect{Boiling point on a mountain} Consider an atmosphere as an ideal gas whose average mass is $30$ gr/mole, with uniform temperature ${T_A=27^oC}$. The atmospheric pressure at sea level ($h=0$) equals $P_0$. \Dn We take liquid whose latent heat is ${Q=1000}$cal/mole, and we find that its boiling point is $105^oC$ at sea level, and $95^oC$ at the top of a mountain. Asume that the gas phase of this liquid is an ideal gas with density much lower than that of the liquid. \Dn (1) Calculate the atmospheric pressure $P_A$ as a function of height $h$. \Dn (2) Calculate the liquid vapor pressure as a function of its temerature. \Dn (3) From above deduce what is the height of the mountain. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%