1. The problem statement, all variables and given/known data A Carnot cycle, shown in Fig. 20-7, has the following conditions: Va = 7.5 L, Vb = 15 L, TH = 470°C, and TL = 260°C. The gas used in the cycle is 0.50 mil of a diatomic gas, y = 1.4. Calculate (a) the pressures at a and b; (b) the volumes at c and d. (The rest of the problem...) 2. Relevant equations PVy = Constant 3. The attempt at a solution I already solved part (a), with Pa = 4.1 x 105 Pa and Pb = 2.1 x 105 Pa. For part (b), I tried PVy = constant nRT⋅Vy-1 = constant. Annnnd then I get lost. I don't understand what constant represents or if I am even on the right track. The book says Vc = 34 L and Vd = 17 L.