How fast do the waves of sound move through the air?
They move at the rate of ten hundred and ninety feet in a second of time, when the temperature of the air is thirty-two degrees.
What effect does warm air have on sound?
Sound travels more rapidly in warm air.
How much does heat increase the velocity of sound?
The velocity of sound is increased one foot in a second of time, for every degree of heat added to the air; so that sound travels eleven hundred and twenty feet in a second, when the temperature is at sixty-two degrees, which is nearly one mile in five seconds.
Does light travel more rapidly than sound?
Yes; light comes from the moon to the earth, a distance of two hundred and forty thousand miles, while sound moves eleven hundred and twenty feet.
What familiar examples of this difference may be given?
A wood-chopper’s axe is seen to descend before we hear the stroke, and the smoke from a gun is seen before we hear the report.