A rigid and well-insulated cylinder is divided into two compartments by a piston which is free to move but does not allow either gas to leak into the other side. Initially, one side of the piston contains 2 m3 of N2 at 250 kPa and 90C, while the other side contains 2 m3 of He at 250 kPa and 30C. Now thermal equilibrium is established in the cylinder as a result of heat transfer through the piston. Using constant volume specific heats at 27C, determine the final equilibrium temperature in the cylinder.