As shown in Fig. P3.60, a rigid, closed tank having a

Chapter 3, Problem 3.60

(choose chapter or problem)

As shown in Fig. P3.60, a rigid, closed tank having a volume of \(20 \mathrm{ft}^{3}\) and filled with 75 lb of Refrigerant 134a is exposed to the sun. At 9:00 a.m., the refrigerant is at a pressure of \(100 \mathrm{lbf} / \mathrm{in} .^{2}\) By 3:00 p.m., owing to solar radiation, the refrigerant is a saturated vapor at a pressure greater than \(100 \mathrm{lbf} / \mathrm{in}^{2}\) For the refrigerant, determine (a) the initial temperature, in \(^{\circ} \mathrm{F}\), (b) the final pressure, in \(\text { lbf/in.2 }\), and (c) the heat transfer, in Btu.