Question

Does the speed of sound increase or decrease on a hotter day?
A. Yes
B. No
C. May be
D. None of these

Answer 1

Hint:The speed of sound mainly affected by two factors: the material that makes up the medium and the temperature of the medium. Recall the relation between kinetic energy of the molecules and temperature. Kinetic energy is proportional to the square of the velocity of the molecules.

Complete answer:
We know that the speed sound changes when it is propagating through a medium other than the air. The speed of sound mainly depends on two factors: the material that makes up the medium and the temperature of the medium. Thus, we have investigated that the speed of sound is affected by the temperature of the air. Now, let’s find out if the speed of sound increases or decreases on hotter days. When the temperature of air increases in the hot summer day, the molecules in the air attain a maximum kinetic energy according to the expression,
\[K = \dfrac{3}{2}kT\],
where, k is the constant and T is the temperature.

We know that the kinetic energy of the molecules is proportional to the square of the velocity. Thus, when the temperature of the air increases, the air molecules move faster in the medium. We know that the sound is propagated in the medium when the vibrations produced by the object are carried by the molecules of the air. Since the air molecules move faster on hotter days, the speed of sound increases.

Hence,option A is the correct answer.

Note:The speed of sound at room temperature is 332 m/s while in the winter days when the surrounding temperature decreases below zero degrees, the speed of sound decreases by the comparatively larger value. The speed of sound also depends on the density of the medium. It is greater in the medium with higher density.