A car is moving towards a high cliff. The car driver sounds a horn of frequency $f$. The reflected sound heard by the driver has a frequency $2f$. If $v$ be the velocity of sound then the velocity of the car, in the same velocity units, will be
A$v/\sqrt 2 $
B$v/2$
C$v/3$
D$v/4$
AIPMT 2004, Diffcult
Download our app for free and get started
C$v/3$
c Frequency of reflected sound heard by driver $n' = n\,\left( {\frac{{v + {v_O}}}{{v - {v_S}}}} \right)$
Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*
If $y_1 = 5 (mm)\ \sin\pi t$ is equation of oscillation of source $S_1$ and $y_2$ $=$ $5$ $(mm)$ $sin(\pi t + \pi /6)$ be that of $S_2$ and it takes $1$ $sec$ and $\frac{1}{2}\ sec$ for the transverse waves to reach point $A$ from sources $S_1$ and $S_2$ respectively then the resulting amplitude at point $A$, is .... $mm$
Two identical flutes produce fundamental nodes of frequency $300\,Hz$ at $27\,^oC.$ If the temperature of air in one flute is increased to $31\,^oC,$ the numbe of the beats heard per second will be
Two trains move towards each other with the same speed. The speed of sound is $340 \;m / s$. If the height of the tone of the whistle of one of them heard on the other changes $9 / 8$ times, then the speed of each train should be ........... $m/sec$
A wave travels on a light string.The equation of the wave is $Y = A \,\sin \,(kx - \omega t + 30^o)$.It is reflected from a heavy string tied to an end of the light string at $x = 0$. If $64\%$ of the incident energy is reflected the equation of the reflected wave is
A police van, moving at $22\, m/s$ , chases a motor-cyclist. The police man sounds horn at $176\, Hz$ , while both of them move towards a stationary siren of frequency $165\, Hz$ as shown in the figure. If the motor-cyclist does not observe any beats, his speed must be .... $m/s$ (take the speed of sound $= 330\, m/s$ )
The length of a sonometer wire is $0.75\, m$ and density $9 \times 10^3\, kg/m^3$. It can bear a stress of $8.1 \times 10^8\, N/m^2$ without exceeding the elastic limit. What is the fundamental frequency that can be produced in the wire .... $Hz$ ?
A speaker emits a sound wave of frequency $f_0$. When it moves towards a stationary observer with speed $u$, the observer measures a frequency $f_1$. If the speaker is stationary and the observer moves towards it with speed $u$, the measured frequency is $f_2$. Then,