$A$ sound wave of frequency $160 \,Hz$ has a velocity of $320 \,m/s$. When it travels through air, the particles having a phase difference of $90^{\circ}$ are separated by a distance of: (in $cm$)

$A$ train, standing in a station-yard, blows a whistle of frequency $400\,Hz$ in still air. The wind starts blowing in the direction from the yard to the station with a speed of $10\,ms^{-1}$. What will be the frequency and speed of sound for an observer? (The speed of sound in still air is $340\,ms^{-1}$)

When sound waves travel from air to water,which of the following remains constant?

Explain which properties are necessary to understand the speed of mechanical waves.

During the propagation of a longitudinal wave,in the region of compressions and rarefactions,

$A$ man standing on a cliff claps his hands and hears the echo after $1 \, s$. If the sound is reflected from another mountain and the velocity of sound in air is $340 \, m/s$,then the distance between the man and the reflection point is ..... $m$.