Home / Aptitude Tests / Physics / THe velocity of soun...

THe velocity of sound in air at 16oC is 340ms-1. What wil...

THe velocity of sound in air at 16oC is 340ms-1. What will it be when the pressure is doubled and its temperature raised to 127ºC?

A.

400 ms-1

B.

4,000 ms-1

C.

8,000 ms-1

D.

160,000 ms-1

Correct answer is A

The velocity of sound in air, V∝√T, where T is absolute temperature
Thus V = K√T or K = V/T
V is independent of pressure and density at a fixed temperature.
∴ V1/√T1 = V2/√T2
T1 = 16 + 273 = 289K, V1 = 340ms-1
T2 = 127 + 273 = 400K, V2 = ?

340 = V2
√289 √400

 

∴ V2 = 340√400
_√289


= 400m/s