1. The problem statement, all variables and given/known data If a piston is compressed, how is the temperature affected? 2. Relevant equations U=Q + W 3. The attempt at a solution My soln: I thought that U=k.e. = (3/2)nRT=(3/2) pV ? Since PV is constant (P1V1=P2V2), shouldnt temperature be constant? Answer sheet: My answer sheet says that Q=0 since piston is insulated. and U=W. Since it is compressed, work is done on the gas, increasing its U, which increases T. Which answer is correct???