Two cars A and B are moving in same direction with speeds 36, km/hr and 54 ,km/hr respect

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14.Waves and Sound

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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 ..... $Hz$

A

$928.57$

B

$984.84$

C

$946.37$

D

$938.47$

Solution

$n^{\prime}=\left(\frac{v-v_{0}}{v-v_{s}}\right) n_{0}=\left(\frac{340-15}{340-10}\right) 1000=984.84 \mathrm{\,Hz}$

Standard 11

Physics

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