Two cars $A$ and $B$ are moving in the same direction with speeds $36\,km/hr$ and $54\,km/hr$ respectively. Car $B$ is ahead of $A$. If $A$ sounds horn of frequency $1000\,Hz$ and the speed of sound in air is $340\,m/s$, the frequency of sound received by the driver of car $B$ is .................. $\mathrm{Hz}$
$928.57$
$985.91$
$946.37$
$938.47$
A closed organ pipe has length $L$ , the air in it is vibrating in third overtone with maximum amplitude $'a'$ . The amplitude at distance $\frac {L}{7}$ from closed end of the pipe is
Two waves $Y_1=A_1 \sin \,(\omega t -\beta_1)$ and $Y_2 = A_2 \sin \,(\omega t -\beta_2)$ superimpose to form a resultant wave whose amplitude is
A railway engine whistling at a constant frequency moves with a constant speed. It goes past a stationary observer standing beside the railway track. The frequency $(n)$ of the sound heard by the observer is plotted against time $(t).$ Which of the following best represents the resulting curve?
The figure represents the instantaneous picture of a transverse harmonic wave traveling along the negative $x$-axis. Choose the correct alternative $(s)$ related to the movement of the nine points shown in the figure. The stationary points is/are
When a wave travels in a medium, the particle displacement is given by : $y = a\,\sin \,2\pi \left( {bt - cx} \right)$ where $a, b$ and $c$ are constants. The maximum particle velocity will be twice the wave velocity if