A source of sound with frequency $f_{0} = 1700 H z$ and an observer are at the same point. At $t = 0$ , the source starts receding from the observer with a constant acceleration $a = 10 m / s^{2}$ . The velocity of the sound in air is $V = 340 m / s$ . then chose the correct option(s).

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

The frequency of sound received by the stationary observer at $t = 10 \sec$ is approximately 1350 HZ

The frequency of sound received by the stationary observer at $t = 10 \sec$ is approximately 1550 HZ

The sound emitted by the source at $t = 6.8 \sec$ (approximately) is received by the stationary observer at $t = 10 \sec$ .

The sound emitted by the source at $t = 8.8 \sec$ (approximately) is received by the stationary observer at $t = 10 \sec$ .

answer is A, D.

(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

Let the sound emitted by the source at time ‘t’ is received by the stationary observer at t =10 sec.
Question Image
$d = \frac{1}{2} a t^{2} = \frac{1}{2} \times 10 t^{2} = 5 t^{2}$
Now, d= 340(10-t)
$5 t^{2} = 340 (10 - t) t^{2} + 68 t - 680 = 0 t = \frac{- 68 \pm \sqrt{{(68)}^{2} + 4 \times 680}}{2}$