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

Your Exam Success, Personally Taken Care Of

1:1 expert mentors customize learning to your strength and weaknesses – so you score higher in school , IIT JEE and NEET entrance exams.

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)

Best Courses for You

JEE

NEET

Foundation JEE

Foundation NEET

CBSE

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)
$5 t^{2} = 340 (10 - t) t^{2} + 68 t - 680 = 0 t = \frac{- 68 \pm \sqrt{{(68)}^{2} + 4 \times 680}}{2}$