Question

What is the speed of sound at 20^oC?

(a) 331.2 m/s

(b) 350 m/s

(c) 343 m/s

(d) 300 m/s

I have been asked this question during an online exam.

Origin of the question is Velocity of Sound or Pressure Wave in a Fluid in section Compressible Flow of Fluid Mechanics

Answer 1

Right option is (c) 343 m/s

Explanation: The speed of sound in dry air at a temperature of 20^oC is equal to 343 m/s. It is found out using the relation of kilometre and miles. One kilometre = 2.91 seconds, and one mile = 4.69 seconds.