An observer starts moving with uniform acceleration$a$, towards a stationary sound source of frequency$f_{0}$. As the observer approaches the source, the apparent frequency(f)heard by the observer varies with time (t)is

Question

Dr. Abubacker · Accepted Answer

(d) Let $v$ be the speed of sound in air, $v_{L}$ velocity of observer at time t. As the observer approaches the source, therefore, apparent frequency
$f = \frac{(v + v_{L})}{v}f_{0} = \left\lbrack \frac{v + (0 + at)}{v} \right\rbrack f_{0} = f_{0} + \left( \frac{f_{0}at}{v} \right)$
This is the equation of a straight line with a positive intercept $\left( f_{0} \right)$and positive slope $\left( \frac{f_{0}a}{v} \right)$. Therefore, option (d) is correct.

Q. An observer starts moving with uniform acceleration$a$, towards a stationary sound source of frequency$f_{0}$. As the observer approaches the source, the apparent frequency(f)heard by the observer varies with time (t)is

Explanation

Reviewed by Dr. Abubacker

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