1. The problem statement, all variables and given/known data The energy of a particular system,of one mole, is given by: U = AP^2 V (A) where A is a positive constant of units [P^(-1)]. Find the equation of the adiabat in the P-V plane 2. Relevant equations I guess dQ = 0 (1) and dU + PdV= 0 (2) 3. The attempt at a solution I tried to express the gien energy equation as fct of P and V, seemed too simple and still being stuck with a U (however on the P-V plane it seemed coherent) so I tried using eq. 2, as dU+Pdv = 0 dU= -PdV integrate: U+U_0 = P (V_0 - V) and substitute in eq. A for U and got P^2(AV) - P(V_0-V)+U_0 = 0 and stuck there, is this a way to go or completely wrong mehod? Its my first problem in this class and I really have a hard time getting the concepts ^^ Thanks for any help.