Ap physics multiple choice practice – thermodynamics 1. the maximum efficiency of a heat engine that operates between temperatures of 1500 k in the firing chamber and 600 k in the exhaust chamber is most nearly (a) 33% (b) 40% (c) 60% ( d) 67% (e) 100% 2. an ideal gas is made up of n diatomic molecules, each of mass m. all of the following statements about this gas are true except: (a) the temperature of the gas is proportional to the average translational kinetic energy of the molecules. (b) all of the molecules have the same speed. (c) the molecules make elastic collisions with the walls of the container. (d) the molecules make elastic collisions with each other. (e) the average number of collisions per unit time that the molecules make with the walls of the container depends on the temperature of the gas.