The speed of sound in dry air at 20ºC is 343 m/s.The speed of sound in dry air at 80ºC is
A)86.0 m/s
B)172 m/s
C)377 m/s
D)686 m/s
E)1.27 km/s

Question

Quizplus · Accepted Answer

The speed of sound in air increases with the temperature. The formula to calculate the speed of sound in air as a function of temperature is $v = 331.4 + 0.6T$, where $v$ is the speed in meters per second and $T$ is the temperature in degrees Celsius. Plugging in 80ºC for $T$, we get $v = 331.4 + 0.6(80) = 331.4 + 48 = 379.4 m/s$. The closest answer to this calculation is 377 m/s, which indicates a slight approximation or rounding in the question or answer choices.

The Speed of Sound in Dry Air at 20ºC Is