An ideal gas of density \rho=0.2 {\kg} {\m}^{-3} enters a chimney of height {\h} at the rate of \alpha=0.8 {\kg} {\s}^{-1} from its lower end, and escapes through the upper end as shown in the figure. The cross-sectional area of the lower end is A_1=0.1 {\m}^2 and the upper end is A_2=0.4 {\m}^2. The pressure and the temperature of the gas at the lower end are 600 {\Pa} and 300 {\K}, respectively, while its temperature at the upper end is 150 {\K}. The chimney is heat insulated so that the gas undergoes adiabatic expansion. Take g=10 {\ms}^{-2} and the ratio of specific heats of the gas \gamma=2. Ignore atmospheric pressure. [JEE Adv 2022 P1]

Question

Examsnet · Accepted Answer

Correct Answer is : The velocity of the gas at the lower end of the chimney is 40ms−1 and at the upper end is 20ms−1

Properties of Matter