Serway & Jewett — The Kinetic Theory of Gases: Problem 2.

Consider the ten objects in our solar system listed below. Using the surface temperatures listed for these objects, determine the average speed of helium atoms located in the atmospheres of these objects. Using data in Table 13.2 and Equation 13.22, determine the escape speed for each of the objects. Finally, take the ratio of the escape speed to the average speed for helium atoms for each object. (a) What is a typical value for this ratio for an object with little to no atmosphere? (b) What is a typical value for this ratio for an object to have a robust atmosphere, but with little to no helium present? (c) What is a typical value for this ratio for an object to have a robust atmosphere with a significant amount of helium? Object Surface Temperature (K) Atmosphere Mercury 440 Little to none Venus 741 Robust, little He Earth 288 Robust, little He Mars 244 Robust, little He Ceres 173 Little to none Jupiter 165 Robust, much He Saturn 134 Robust, much He Uranus 77 Robust, much He Neptune 70 Robust, much He Pluto 40 Little to none