A rocket is moving at a speed of \(130 \mathrm{~m} / \mathrm{s}\) towards a stationary target. While moving, it emits a wave of frequency $800 \mathrm{~Hz}$. Calculate the frequency of the sound as detected by the target. (Speed of wave \(=330 \mathrm{~m} / \mathrm{s}\) ) (A) \(1320 \mathrm{~Hz}\) (B) \(2540 \mathrm{~Hz}\) (C) \(1270 \mathrm{~Hz}\) (D) \(660 \mathrm{~Hz}\)

Short Answer

Expert verified
The frequency of the sound as detected by the target is (A) \(1320 \mathrm{~Hz}\).

Step by step solution

01

Understand the Doppler effect formula for sound waves

The Doppler effect formula for sound waves is given by: \[f' = f \frac{v + v_0}{v + v_s}\] Here, \(f'\) = Apparent frequency detected by the target \(f\) = Source frequency (800 Hz) \(v\) = Speed of the sound wave (330 m/s) \(v_0\) = Speed of the target (0 m/s, as it is stationary) \(v_s\) = Speed of the source (the rocket), (positive when the source moves away from the observer and negative when it moves towards)
02

Plug the given values into the formula

We know the source frequency, speed of the sound wave, and speed of the rocket, so we can plug these values into the formula. Since the rocket is moving towards the target, the speed of the source will be negative. Hence, \(v_s = -130 \mathrm{~m / s}\).
03

Calculate the apparent frequency

Now, we can plug all these values into the Doppler effect formula and find the apparent frequency detected by the target. \[f' = 800 Hz \frac{330 m/s + 0}{330 m/s - 130 m/s}\]
04

Simplify and find the answer

Simplifying the equation, we get \[f' = 800 Hz \frac{330 m/s}{200 m/s}\] \[f' = 800 Hz \cdot \frac{33}{20}\] \[f' = 1320 Hz\] So, the frequency of the sound as detected by the target will be \(1320 Hz\). Therefore, the correct answer is (A) \(1320 \mathrm{~Hz}\).

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

A small spherical steel ball is placed at a distance slightly away from the center of a concave mirror having radius of curvature \(250 \mathrm{~cm}\). If the ball is released, it will now move on the curved surface. What will be the periodic time of this motion? Ignore frictional force and take $\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^{2}$. (A) \((\pi / 4) \mathrm{s}\) (B) \(\pi \mathrm{s}\) (C) \((\pi / 2) \mathrm{s}\) (D) \(2 \pi \mathrm{s}\)

The equation for displacement of a particle at time \(\mathrm{t}\) is given by the equation \(\mathrm{y}=3 \cos 2 \mathrm{t}+4 \sin 2 \mathrm{t}\). The amplitude of oscillation is \(\ldots \ldots \ldots . \mathrm{cm}\). (A) 1 (B) 3 (C) 5 (D) 7

A particle executing S.H.M. has an amplitude \(\mathrm{A}\) and periodic time \(\mathrm{T}\). The minimum time required by the particle to get displaced by \((\mathrm{A} / \sqrt{2})\) from its equilibrium position is $\ldots \ldots \ldots \mathrm{s}$. (A) \(\mathrm{T}\) (B) \(\mathrm{T} / 4\) (C) \(\mathrm{T} / 8\) (D) \(\mathrm{T} / 16\)

A tuning fork of frequency \(480 \mathrm{~Hz}\) produces 10 beats/s when sounded with a vibrating sonometer string. What must have been the frequency of the string if a slight increase in tension produces fewer beats per second than before? (A) \(480 \mathrm{~Hz}\) (B) \(490 \mathrm{~Hz}\) (C) \(460 \mathrm{~Hz}\) (D) \(470 \mathrm{~Hz}\)

In a longitudinal wave, pressure variation and displacement variation are (A) In phase (B) \(90^{\circ}\) out of phase (C) \(45^{\circ}\) out of phase (D) \(180^{\circ}\) out of phase

See all solutions

Recommended explanations on English Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free