Question

Exercise 4

Exercise-4 Yutong has a closed cylindrical can with radius r 12.0em and height of H 20.0em containing Xe gas at a temperature of 22.00. She uses a candle to heat up the can and add ΔQ 10.0] of heat energy to the gas. (a) What is the temperature of the gas after Yutong has added the 10.0J of heat energy to it? (b) What is the pressure of the gas in the can after adding this energy? Exercise-5 Illarion is designing a thermo-elevator that will use heating of a gas to lift people up inside buildings. It's basically a big cylinder filled with nitrogen gas that has a plunger in it that people will stand on with the gas underneath the plunger. The plunger moves up or down as the gas expands or contracts upon the addition or removal of heat from the gas. Suppose that the plunger itself has a mass of 250.kg, and that Illarion would like to be able to lift 350.kg worth of people up to their rooms at a rate of 1.,00m/s How much thermal power (heat energy per second) would be required to do this?

Answer 1

Delta 2 = 10 J xe-gas Monoatomic c_v = 3/2 R delta 2 = c_v (T_1 - T_2) 10 = 3/2 R (T_2 - 295) 20/3R + 295 = T_2 T_2 = 20/3 times 8.314 + 295 T_2 = 295.8 k = 22.8 degree c Now V = pi r^2 h = 3.14 times (12 times 10^-2)^2 20 times^-2 V = 9.04 times 10^-3 m^3 Now, P_1 V_1 = nRT_1, n = 1 P_1 = R T_1/V_1 = 8.314 times 295/9.04 times 10^-3 = 2.7 times 10^5 N/m^2 \r\n P_1 V_1/P_2 V_2 = RT_1/RT_2, V_1 = V_2 P_2 = T_2, P_1/T_1 = 295.8/295 = 2.7 times 10^5 N/m^2 [P_2 = 2.71 times 10^5 N/m^2]