Air with initial condition of $P_1, V_1$ expands to final condition of $P_1/2, 3V_1$. The process is
- A. Hyperbolic
- B. Adiabatic
- C. Polytropic with n > 1
- D. Polytropic with n < 1
Answer: D. Polytropic with n < 1
Explanation: $P_1 V_1^n = P_2 V_2^n \Rightarrow P_1 V_1^n = (P_1/2) (3V_1)^n \Rightarrow 2 = 3^n$. $\ln 2 = n \ln 3 \Rightarrow n = \ln 2 / \ln 3 \approx 0.63 < 1$.