Whether can we apply c = va to sound waves ?

Why do we apply paint of iron articles ?

When we apply brakes to car then travels with ………………..

Can we apply this equation c = upsilon lambda , to a sound wave '?

A vertical tube is made to stand in water so that the waterlevel can be adjusted . Sound waves of frequency 320 Hz are sent into the top of the tube.If standing waves are produced at two successive water levels of 20cm and 73cm, what is the speed of sound waves in the air in the tube ?

Find the time period of a source of a sound wave whose frequency is 400 Hz.

(A): Radio waves can be polarized (R): Sound waves in air longitudinal in nature.

(A ): The light can travel in vacuum but sound cannot do so (R) : Light is an electromagnetic wave and sound is a mechanical wave