Two sources $A$ and $B$ are producing notes of frequency $680 \,Hz$. $A$ listener moves from $A$ to $B$ with a constant velocity $v$. If the speed of sound in air is $340 \,ms^{-1}$, the value of $v$ so that he hears $10$ beats per second is: (in $\,ms^{-1}$)

Two sources of sound $S_1$ and $S_2$ are moving towards and away from a stationary observer with the same speed $V$ respectively. The observer detects $3$ beats per second. Find the speed of the source (approximately) in $m/s$. Given: $f_1 = f_2 = 500 \, Hz$,speed of sound in air $= 330 \, m/s$.

$Assertion :$ The Doppler formula for sound waves is symmetric with respect to the speed of the source and the speed of the observer.
$Reason :$ The motion of a source with respect to a stationary observer is not equivalent to the motion of an observer with respect to a stationary source.

$A$ reflector is moving with $20 \,m/s$ towards a stationary source of sound. If the source is producing sound waves of $160 \,Hz$, then the wavelength of the reflected wave is (speed of sound in air is $340 \,m/s$).

Two cars moving in opposite directions approach each other with speeds of $22 \, m s^{-1}$ and $16.5 \, m s^{-1}$ respectively. The driver of the first car blows a horn having a frequency of $400 \, Hz$. The frequency heard by the driver of the second car is ..... $Hz$ (velocity of sound is $340 \, m s^{-1}$)

$A$ train blowing its whistle moves with constant speed on a straight track towards an observer and then crosses him. If the ratio of the difference between the actual and apparent frequencies is $3:2$ in the two cases (approaching and receding),then the speed of the train is (where $v$ is the speed of sound).