/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 79 The phase difference between two... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

The phase difference between two points separated by \(0.8 \mathrm{~m}\) in a wave of frequency \(120 \mathrm{~Hz}\) is \(0.5 \pi\). The wave velocity is (A) \(144 \mathrm{~m} / \mathrm{s}\) (B) \(256 \mathrm{~m} / \mathrm{s}\) (C) \(384 \mathrm{~m} / \mathrm{s}\) (D) \(720 \mathrm{~m} / \mathrm{s}\)

Short Answer

Expert verified
To find the wave velocity, first calculate the wavelength using the given phase difference and distance between two points: Wavelength = \(\dfrac{2\pi \times 0.8}{0.5\pi} = 3.2 \)m. Then, use the formula for wave velocity: Velocity = Frequency × Wavelength, and substitute the given values: Velocity = \(120 \mathrm{Hz} \times 3.2 \mathrm{m} = 384 \mathrm{m/s}\). The correct answer is (C) \(384 \mathrm{~m} / \mathrm{s}\).

Step by step solution

01

1. Remember the formula for wavelength and phase difference

Using the formula for phase difference, we have: Phase Difference = \(\dfrac{2\pi\times Distance}{Wavelength}\). We can rearrange this equation to find the wavelength: Wavelength = \(\dfrac{2\pi\times Distance}{Phase Difference}\).
02

2. Substitute the given values into the equation

We have the phase difference (0.5\(\pi\)) and the distance (0.8 m). Substituting these values into the equation, we get: Wavelength = \(\dfrac{2\pi \times 0.8}{0.5\pi}\).
03

3. Calculate the wavelength

Now, we need to calculate the wavelength. After solving the equation, we get: Wavelength = \(\dfrac{2\pi \times 0.8}{0.5\pi} = \dfrac{1.6\pi}{0.5\pi} = 3.2 \)m.
04

4. Use the formula for wave velocity

Now that we have the wavelength and frequency, we can use the formula for wave velocity: Velocity = Frequency × Wavelength.
05

5. Calculate the wave velocity

Substituting the given frequency (120 Hz) and the calculated wavelength (3.2 m) into the formula, we get: Velocity = \(120 \mathrm{Hz} \times 3.2 \mathrm{m} = 384 \mathrm{m/s}\). So the correct answer is (C) \(384 \mathrm{~m} / \mathrm{s}\).

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 91Ó°ÊÓ!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Phase Difference
Phase difference represents the relative offset in the oscillation cycles of two points within a wave. It's a crucial concept to understand because it affects how waves interact with each other, resulting in phenomena such as constructive or destructive interference. Imagine two waves reaching a point at different times; the phase difference quantifies this discrepancy. Mathematically, it's often measured in radians (as in the exercise where it's given as \(0.5 \times \rpi\)) and can be calculated using the formula:
\[ \text{Phase Difference} = \dfrac{2\rpi\times \text{Distance}}{\text{Wavelength}} \]
When waves are in phase, their peaks and troughs align, intensifying the overall wave effect. In contrast, when they are out of phase, their peaks and troughs may cancel out, reducing or negating the wave effect.
Wavelength Calculation
Wavelength is the distance between two consecutive points that are in phase on a wave, such as between two peaks or two troughs. Calculating wavelength is fundamental for understanding the physical properties of waves and how they propagate. To determine wavelength from phase difference, we can simply rearrange the previous formula:
\[\text{Wavelength} = \dfrac{2\rpi\times \text{Distance}}{\text{Phase Difference}} \]
It's essential to ensure that the units of distance match up with the desired units for wavelength. This calculation plays a vital role in various applications, from analyzing sound waves to determining the properties of electromagnetic radiation. In our textbook exercise, we've seen this calculation in action, demonstrating how to deduce the wavelength from the given phase difference and the distance between two points on the wave.
Wave Frequency
Wave frequency, measured in hertz (Hz), indicates how many oscillation cycles occur in a wave per second. It's a direct measure of the 'speed' of the wave's oscillation. A higher frequency means more cycles per second, equating to a higher-pitched sound in acoustics or more energy in electromagnetic waves. The frequency is an inherent property of a wave that, along with wavelength, helps to determine the wave velocity through the relation:
\[ \text{Velocity} = \text{Frequency} \times \text{Wavelength} \]
Therefore, knowing the frequency enables us to solve for wave velocity if the wavelength is known, as demonstrated in the exercise where the wave's frequency was a key data point in calculating its velocity. Remembering that wave velocity can also be influenced by the medium through which the wave travels adds another layer of complexity and importance to understanding this concept.

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 sonometer wire is in unison with a tuning fork in fundamental mode. Keeping the same tension, the length of wire between the bridges is doubled. The tuning fork can still be in resonance with the wire, provided the wire now vibrates in (A) 4 segments (B) 6 segments (C) 3 segments (D) 2 segments

Motion of an oscillating liquid column in an U-tube is (A) periodic but not simple harmonic. (B) non-periodic. (C) simple harmonic and time period is independent of the density of the liquid. (D) simple harmonic and time period is directly proportional to the density of the liquid.

An open organ pipe has a fundamental frequency of \(240 \mathrm{vib} / \mathrm{s}\). The first overtone of a closed organ pipe has the same frequency as the first overtone of the open pipe. How long is each pipe? Velocity of sound at the room temperature is \(350 \mathrm{~ms}\).

A closed organ pipe of length \(L\) is vibrating in its first overtone. There is a point \(Q\) inside the pipe at a distance \(7 L / 9\) from the open end. The ratio of pressure amplitude at \(Q\) to the maximum pressure amplitude in the pipe is (A) \(1: 2\) (B) \(2: 1\) (C) \(1: 1\) (D) \(2: 3\)

A tuning fork of known frequency \(256 \mathrm{~Hz}\) makes 5 beats per second with the vibrating string of a piano. The beat frequency decreases to 2 beats per second when the tension in the piano string is slightly increased. The frequency of the piano string before increasing the tension was (A) \(261 \mathrm{~Hz}\) (B) \(258 \mathrm{~Hz}\) (C) \(254 \mathrm{~Hz}\) (D) \(251 \mathrm{~Hz}\)

See all solutions

Recommended explanations on Physics 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.