Question

A sound wave is created in an unknown substance with a frequency of 24kHz. Using extremely sensitive sensors, it is determined that the sound wave travels through a piece of this substance that is 3.5 m long in .919 millisecond. Determine the substance that this sound wave is traveling through.

Answer 1

velocity is of sound id defined as distance covered by sound per unit time

here given that

distance covered by sound = 3.5 m

time taken by the sound = 0.919 millisecond

So the velocity of sound will be given as

$v = \frac{d}{t}$

$v = \frac{3.5}{0.919* 10^{-3}}$

$v = 3808.5 m/s$

so the speed of sound in the given medium is 3808.5 m/s

As we know that speed of sound in any substance is given as

$v = \sqrt{\frac{E}{\rho}}$

As per the data available online the speed of sound in gold is 3250 m/s while speed of sound in glass is 4500 m/s

So here we can say the above speed is in between these two mediums whose elasticity and density ratio is more than gold but less than glass.

So this velocity of sound is nearly match with the data obtained for copper

So this speed is approx obtained in copper