Question

Arrange the speed of sound in decreasing order in three mediums: wood, water and air.
(A) wood > air > water
(B) wood > water > air
(C) water > wood > air
(D) air > water > wood

Answer 1

The sound waves will travel through the medium by continuously changing contracting and then expanding the parts in the medium in which the waves travel. The velocity of the sound is the distance travelled by the sound waves per unit time.
Useful formula:
The speed of the sound is given by,
$v = \sqrt {\dfrac{{\chi P}}{\rho }}$
Where, $v$ is the velocity or speed of the sound waves, $\chi$ is the coefficient of the adiabatic expansion, $P$ is the pressure of the gas and $\rho$ is the density of the medium.

Complete answer:
Given that,
The sound wave is passed in the three different mediums. And the mediums are wood, water and air.
The given three mediums are having three different densities and by using the formula, the decreasing order in three mediums can be found. The density of the wood is greater than the water and air. The density of the water is greater than the air.
Now,
The speed of the sound is given by,
$v = \sqrt {\dfrac{{\chi P}}{\rho }} \,................\left( 1 \right)$
By the above equation (1), the velocity or the speed of the sound is inversely proportional to the density. So, if the density of the material is higher, then the velocity or the speed of the sound is smaller. So, that the velocity of the sound is greater in air and then in water and then in wood.
air > water > wood.

Hence, the option (D) is the correct answer.

Note:
The speed of sound is characterized as the dynamic engendering of sound waves. This relies upon the attributes of the medium through which the engendering happens. Speed of sound is utilized for portraying the speed of sound waves in a versatile medium.