Consider a tall vertical cylindrical container of height "H" at atmospheric pressure. A precisely fitted plug is dropped into the cylinder and falls - compressing the air. After a brief period of oscillation the plug settles to a height "h=H/2." Assume the air behaves as an ideal gas and this takes place at 27 C.
We now raise the temperature of the cylinder very slowly, causing the air to expand raising the piston. What is the temperature just before the piston reaches the top of the cylinder?