When a train is approaching the stationary observer, the apparent frequency of the whistle is observed as 100 Hz, while when it passes away from the observer with same speed, it is 50 Hz. The frequency of the whistle when the observer moves with the train _______ $H z$ . (speed of sound = 330 m/s)
[Round-off the answer to two decimal places]

see full answer

Talk to JEE/NEET 2025 Toppers - Learn What Actually Works!

Real Strategies. Real People. Real Success Stories - Just 1 call away

An Intiative by Sri Chaitanya

answer is 66.67.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

$f_{1} = f_{0} (\frac{V}{V - V_{s}}) \Rightarrow 100 = f_{0} (\frac{V}{V - V s})$ -------(1)
$f_{2} = f_{0} (\frac{V}{V + V_{s}}) \Rightarrow 50 = f_{0} (\frac{V}{V + V s})$ ------- (2)
Eqn (1) and (2)
$\frac{100}{50} = \frac{V + V_{s}}{V - V_{s}} \Rightarrow V_{S} = 110 m / s$
Sun in eqn (1), $f_{0} = 66.67 H z$