Dear Tom,
Is the speed of sound in any way affected by temperature?
Robert Lucas, Homer Glen
Dear Robert,
It certainly is. Sound travels faster in warm air than cold air. This occurs because as the air temperature increases the speed of the air molecules also increases. This results in more frequent collisions between the molecules, allowing them to propagate the sound waves in a shorter period of time. At 0(degrees)F the speed of sound in air is about 717 m.p.h., but at 50(degrees)F it increases to about 755 m.p.h. and reaches about 791 m.p.h. at 100(degrees)F. In general, the speed of sound in air will increase by a little more than 7 m.p.h. for every 10F rise in temperature. The speed of sound can increase dramatically when it moves through media denser than air. In water, sound travels about four times faster than it does in air, and in steel its speed is about 15 times faster.
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Tom Skilling is chief meteorologist at WGN-TV. His forecasts can be seen Monday through Friday on WGN-TV News at noon and 9 p.m.
Write to: ASK TOM WHY, 2501 Bradley Pl., Chicago, IL 60618 or asktomwhy@wgntv.com (Mail volume precludes personal response.)
WGN-TV meteorologists Steve Kahn, Richard Koeneman and Paul Dailey plus weather producer Bill Snyder contribute to this page.
