Question

Which statement is true?
A.The speed of sound in air is inversely proportional to the temperature of the air.
B.The speed of sound in air is directly proportional to the temperature of the air.
C.The speed of sound in air is twice the temperature of the air.
D.The speed of sound in airis not affected by the temperature of the air.

Answer 1

The speed of sound increases when the temperature increases. Thus, they are directly proportional! I believe this is because the hot air is less dense....

Answer 2

"The speed of sound c depends on the temperature of air and not on the air pressure!
The humidity of air has some negligible effect on the speed of sound. The air pressure
and the density of air (air density) are proportional to each other at the same temperature.
It applies always p / ρ = constant. rho is the density ρ and p is the sound pressure.
Therefore air pressure does not enter into the calculation of the speed of sound of air."
- http://www.sengpielaudio.com/calculator-speedsound.htm

Answer 3

"The sound of speed in air is increased by 0.60 m/s for each increase of degree in air temperature."
- http://hypertextbook.com/facts/2000/CheukWong.shtml
This is evidence of the direct proportionality.

Answer 4

Its D?

Answer 5

Hehe, the answer is in my first post.

Answer 6

But it's not an issue of density, I read. It's an issue of how many collisions are heppening in the air that the sound travels through.

"The average mean speed of the molecules of air is faster in warm air than on cool air. Sound is transferred by collisions of molecules. Therefore sound waves will travel faster on warm air because collisions of molecules of air in warm air is greater."
- http://wiki.answers.com/Q/Why_does_sound_travel_faster_in_warm_air_than_cold_air