Posted by Anonymous on Friday, May 6, 2011 at 4:01pm.
A scuba diver takes a tank of air on a deep dive. The tank's volume is 10 L and it is completely filled with air at an absolute pressure of 224 atm at the start of the dive. The air temperature at the surface is 92 F and the diver ends up in deep water at 50 F. Assuming thermal equilibrium and neglecting air loss, determine the absolute internal pressure of the air when it is cold.

Physics  drwls, Friday, May 6, 2011 at 4:25pm
P/T is a constant at constant (tank) volume and amount (moles) of gas. T must be an absolute temperature. Either Kelvin or Rankine will work.
T1 = 92F = 552 R
T2 = 50F = 510 R
"R" is the absolute Rankine temperature. You get it by adding 460 to the Fahrenheit temperature.
P2/P1 = T2/T1 = 510/552 = 0.9239
P2 = 207 atm