Two cars moving in opposite directions approa | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(B) The apparent frequency $v^{\prime}$ heard by the observer is given by the Doppler effect formula for sound:$v^{\prime} = v \left( \frac{v + v_{o}}

Vedclass · Accepted Answer

$448$

Vedclass · Answer

(B) The apparent frequency $v^{\prime}$ heard by the observer is given by the Doppler effect formula for sound:$v^{\prime} = v \left( \frac{v + v_{o}}{v - v_{s}} ight)$Here,the velocity of sound $v = 340 \, m s^{-1}$.The source is the first car,so $v_{s} = 22 \, m s^{-1}$.The observer is the second car,so $v_{o} = 16.5 \, m s^{-1}$.The source frequency $v = 400 \, Hz$.Substituting the values into the formula:$v^{\prime} = 400 \left( \frac{340 + 16.5}{340 - 22} ight)$$v^{\prime} = 400 \left( \frac{356.5}{318} ight)$$v^{\prime} = 400 	imes 1.121069...$$v^{\prime} \approx 448.42 \, Hz$Rounding to the nearest integer,the frequency heard is $448 \, Hz$.

Similar Questions

$A$ source of sound emitting a note of frequency $200 Hz$ moves towards an observer with a velocity $v$ equal to the velocity of sound. If the observer also moves away from the source with the same velocity $v$,the apparent frequency heard by the observer is .... $Hz$

$A$ boy is walking away from a wall towards an observer at a speed of $1\, m/s$ and blows a whistle whose frequency is $680\, Hz$. The number of beats heard by the observer per second is (Velocity of sound in air $= 340\, m/s$).

$A$ vehicle sounding a whistle of frequency $256 \,Hz$ is moving on a straight road towards a hill with a velocity of $10 \,ms^{-1}$. The number of beats per second observed by a person travelling in the vehicle is (velocity of sound $= 330 \,ms^{-1}$).

The frequency changes by $10 \%$ as a sound source approaches a stationary observer with constant speed $V_s$. What would be the percentage change in the frequency as the source recedes from the observer with the same speed $\left(V_s < V\right)$ (in $.5$)?

$A$ train is moving with a uniform speed $33 \ m/s$ and an observer is approaching the train with the same speed. If the train blows a whistle of frequency $1000 \ Hz$ and the velocity of sound is $333 \ m/s$, then the apparent frequency of the sound that the observer hears is: (in $Hz$)

Vedclass Test Series

Exam Paper Generator

Online Exam Module