The speed of sound in air (in m/s) depends on the temperature according to the a
ID: 1273159 • Letter: T
Question
The speed of sound in air (in m/s) depends on the temperature according to the approximate expression below, where Tq is the Celsius temperature. In dry air the temperature decreases about 1degreeC for every 150 m rise in altitude. v = 331.5 + 0.607TC Assuming this change is constant up to an altitude of 9000 m, how long will it take the sound from an airplane at 7400 m to reach the ground on a day when the ground temperature is 31degreeC? Compare this to the time interval required if the air were constant at 31degreeC. Which time interval is longer? air at constant temperature air at changing temperatureExplanation / Answer
a)
v=331.5+0.607*Tc
at Tc=31
v=331.5+0.607*31
=350.317 m/s
time = distance/v
=9000/350.317
=25.7 s
Ans: 25.7 s
b)
air at changing temperature