Water is about 800 times as dense as air and about 15,000 times as stiff. If sound in air travels at about 760 mph., what is the speed of sound under water?
A) 176.7 mph.
B) 3268 mph.
C) 760 mph.
D) 800 mph.

Question

Quizplus · Accepted Answer

The speed of sound in a medium is proportional to the square root of the stiffness (bulk modulus) of the medium divided by its density. Given that water is about 15,000 times as stiff and 800 times as dense as air, the increase in stiffness would greatly outweigh the increase in density, leading to a higher speed of sound in water. The correct calculation, taking into account these factors, would result in a speed significantly greater than in air, making 3268 mph a plausible value for the speed of sound under water.

Water Is About 800 Times as Dense as Air and About