A meteorological field team is conducting acoustic tests on a still winter morning (air assumed dry). Shortly after sunrise the measured air temperature at instrument height is −5∘C. By early afternoon the air temperature has risen to +15∘C. The team wants to understand how these conditions influence the transmission of sound produced by their equipment.
(a) Qualitatively compare the speed at which sound waves propagate through the air at −5∘C and at +15∘C. State which condition yields the larger speed and briefly describe the observable consequences for the time required for sound to cover a fixed distance.
(b) Using ideas from the molecular‐kinetic model of an ideal gas, explain why the difference in temperature leads to the difference in sound speed you described in part (a). In your explanation, discuss how temperature affects molecular rms speed, intermolecular collision rates, and the restoring forces that give rise to longitudinal pressure disturbances.