Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Why is sound faster in warm air?
Name: Steve H.
Status: N/A
Age: N/A
Location: N/A
Country: N/A
Date: Around 1993


Question:
Why does sound travel faster in warm air than in cool air?



Replies:
of 2 The warmer the air is the greater the average mean speed of the molecules of air. Since sound is transferred by collisions of molecules, the quicker they move the sooner the collisions transfer the sound energy down the path.

gfb


The traveling of sound depends on the forces between the atoms or molecules of the medium, and in a gas those force only act during the short period when they collide. But in liquids and solids the fundamental question is how fast the atoms jiggle around in their local positions (sound waves are actually coordinated long-wavelength "jiggles") which gets faster the higher the strength of the local forces keeping the atoms roughly in place. So, sound travels fastest in the most strongly bonded materials.

A. Smith



Click here to return to the Physics Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs

NEWTON AND ASK A SCIENTIST
Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory