Question

Physics 107 Homework 8 (Chapter 9, Statistical Physics) (Room Temperature - 300 ) la. Find the average translational kinetic energy of a Helium atom in thermal equilibrium, at room temperature, in eV. b. Find the average translational kinetic energy of a 1 kg octopus in thermal equilibrium, at room temperature, in eV. c. Find the mean speed of an He atom in thermal equilibrium, at room temperature. d. Find the mean speed of a 1 kg octopus in thermal equilibrium, at room temperature. 2. Let's assume we have a gas of N diatomic molecules at a temperature T; which is sufficiently high that all degrees of freedom of the molecules are activated. If we let the gas mix with a gas of N Helium atoms at T= 0, and let the mixture come to thermal equilibrium, what would be the final temperature of the gas Te You can assume Tfis still high enough that all degrees of freedom of the molecules are activated. 3. Let's assume we have a gas of N diatomic molecules at a temperature Ti which is sufficiently hie vated. If we extract heat from the gas such that the gas cools down degrees of freedom of the molecules are activated. If we extract heat from the gas such that the ga to a temperature T that is sufficiently low that the rotational and vibrational degrees of freedom how much energy has been lost from the gas? pal degrees of freedom are frozen out, excite Li from the 2s ground state 4. We have a gas of lithium atoms. The wavelength of the photon needed to excite Li from the to the 2p excited state is 2 = 671 nm. a. What is the energy difference between the 2s and 2p states? b. When you include the number of Ly states, how many states are there for the 2s versus 20 c. Find the ratio of Li atoms in 2p to 2s states at room temperature. d. Find the temperature you would need to make the ratio 1 to 1000. 5. Which of the following narticles are Roone 1'1 1

Question 3 please

Answer 1

Af sufficiently large Temperature, There are 6 degree of freedom of a diatomic molecule, in which (3) are Translational, (2) are Rorational and (1) is vibrational. using maxwell - Beltzmann's Dixtribution, ane diatonic molecule contains Energy (E) E = 6x {K Ti Eo = 3KT, k= 1138x10 23 J/k = Boltzmann's constant Then Toral Initial Energy Ei = 3NKT; -O sina at degrees of low temperature freedom frozen rorational and vibrational out Therefore toral Energy B = ENKTE - ©

Enera on fem (бал ТЕ. Е. -Е. DE EINKTA - 3 NK T; (se - знь (т- )) Алекс