If a supersonic plane is flying at increasing speed as the temperature decreases, what happens to the Mach number in this instance?
A) It stays the same.
B) It increases.
C) It decreases.
D) It can do any of the above.
E) It can do either (a) or (b) but not (c).

Question

Quizplus · Accepted Answer

The Mach number, which is the ratio of the speed of the object to the speed of sound in the medium, increases as the speed of the object increases or as the speed of sound decreases. Since the speed of sound decreases with a decrease in temperature, and the plane's speed is increasing, both factors contribute to an increase in the Mach number.

If a Supersonic Plane Is Flying at Increasing Speed as the Temperature