/*! 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 9 If you shake the end of a stretc... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

If you shake the end of a stretched spring up and down with a frequency \(f,\) you can produce a sinusoidal, transverse wave propagating down the spring. Does the wave number depend on the frequency you are shaking the spring?

Short Answer

Expert verified
The wave number (k) depends on the frequency (f) at which the spring is being shaken, as shown by the equation \(k = \frac{2\pi f}{v}\), where \(v\) is the wave speed. Since k is directly proportional to f and inversely proportional to v, increasing the frequency will result in an increase in the wave number.

Step by step solution

01

Understand the properties of sinusoidal waves

A sinusoidal wave is a wave that oscillates in a sinusoidal pattern, which includes waves such as sound waves, light waves, and spring waves. The main properties of sinusoidal waves are amplitude, wavelength, frequency, wave speed, and wave number.
02

Know the definition of wave number

The wave number (k) is defined as the number of wavelengths per unit distance, or the spatial frequency of the wave. It's mathematically expressed as: \[k = \frac{2\pi}{\lambda}\] where \(\lambda\) is the wavelength of the wave.
03

Establish the relationship between wave speed, frequency, and wavelength

In general, for any wave, the product of its wavelength and frequency equals the wave speed: \[v = \lambda f\] where \(v\) is the wave speed, \(\lambda\) is the wavelength, and \(f\) is the frequency.
04

Determine the dependence of wave number on frequency

From the relationship between wave speed, frequency, and wavelength, we can write the wavelength as: \[\lambda = \frac{v}{f}\] Now, substitute this expression for \(\lambda\) in the formula for wave number: \[k = \frac{2\pi}{\lambda} = \frac{2\pi}{\frac{v}{f}} = \frac{2\pi f}{v}\] From this equation, we can see that the wave number (k) is directly proportional to the frequency (f) and inversely proportional to the wave speed (v). Therefore, the wave number does depend on the frequency at which the spring is being shaken.

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.

Sinusoidal Waves
Sinusoidal waves hold a special place in the study of waves and motion. These waves, characterized by their smoothly repetitive oscillation, are a fundamental pattern found in various types of waves, including sound, light, and even the ripples on a spring. Picture a sine wave from a graph of a trigonometric function; it rises and falls with consistency and symmetry. This is why we liken these physical waves to the mathematical sine function, hence the name 'sinusoidal'. The wave pattern of a sinusoidal wave is determined by several parameters, such as amplitude, which represents the wave's maximum displacement from its rest position.

A crucial aspect of these waves is that they are predictable and thus allow for clear mathematical descriptions of their properties. Whether in the context of a physics lab or natural phenomena, the characteristics of sinusoidal waves help us understand how different waves can move through various mediums, such as the coils of a spring, the air, or even the vacuum of space.
Wavelength
Wavelength is a central concept when discussing sinusoidal waves. It is defined as the distance between successive crests or troughs of a wave – think of it as the 'length' of one complete wave cycle. Expressed in meters or centimeters, the wavelength \textbf{(represented by the Greek letter lambda, \(\lambda\))}, helps determine other properties of the wave. For instance, in the scenario of a spring, if you were to mark one crest and measure the distance to the next crest, you'd have the wavelength of the wave.

Understanding wavelength allows us to comprehend the spatial extent of waves and also plays a role in determining the energy of a wave; typically, shorter wavelengths correspond to higher energies. In various applications such as optics, acoustics, and even communication technologies, wavelength is a critical factor to consider.
Frequency
Frequency is commonly described as the number of wave cycles that occur in one second. It is the 'heartbeat' of the wave, dictating how often the wave oscillates back and forth. Measured in Hertz (Hz), frequency can be thought of like the tempo of music—higher frequency means more wave cycles in a given time, resulting in a higher pitch in sounds or a bluer color in light.

In practical terms, frequency affects how waves behave and interact with different materials. For instance, microwaves have a specific frequency that allows them to interact with water molecules to heat food. Furthermore, in communications, different frequencies are used to transmit signals without interference, showcasing the importance of this parameter.
Wave Speed
Finally, discuss wave speed – the rate at which a wave travels through a medium. It's the speed with which the crests and troughs of a sinusoidal wave move along the spring. This speed is dependent on the medium itself (its density, elasticity, and other properties) as well as the type of wave. Sound travels at a different speed in air than it does in water or steel, for instance.

For waves to be harnessed in technology, understanding wave speed is vital. This can apply to everything from designing buildings that withstand earthquakes to creating instruments that accurately map the ocean floor. Importantly, wave speed is intrinsic to the relationship between frequency and wavelength because it is the product of the two \(v = \lambda f\). This intertwining of properties demonstrates the harmonized nature of wave behavior and is crucial for students to grasp when studying wave dynamics.

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

What is the wavelength of an earthquake that shakes you with a frequency of \(10.0 \mathrm{Hz}\) and gets to another city 84.0 km away in 12.0 s?

A string with a length of 4 m is held under a constant tension. The string has a linear mass density of \(\mu=0.006 \mathrm{kg} / \mathrm{m} .\) Two resonant frequencies of the string are \(400 \mathrm{Hz}\) and \(480 \mathrm{Hz}\). There are no resonant frequencies between the two frequencies. (a) What are the wavelengths of the two resonant modes? (b) What is the tension in the string?

a) What is the intensity of a laser beam used to burn away cancerous tissue that, when \(90.0 \%\) absorbed, puts \(500 \mathrm{J}\) of energy into a circular spot \(2.00 \mathrm{mm}\) in diameter in 4.00 s? (b) Discuss how this intensity compares to the average intensity of sunlight (about) and the implications that would have if the laser beam entered your eye. Note how your answer depends on the time duration of the exposure.

A copper wire has a density of \(\rho=8920 \mathrm{kg} / \mathrm{m}^{3},\) a radius of \(1.20 \mathrm{mm},\) and a length \(L .\) The wire is held under a tension of \(10.00 \mathrm{N}\). Transverse waves are sent down the wire. (a) What is the linear mass density of the wire? (b) What is the speed of the waves through the wire?

A string is 3.00 m long with a mass of 5.00 g. The string is held taut with a tension of \(500.00 \mathrm{N}\) applied to the string. A pulse is sent down the string. How long does it take the pulse to travel the \(3.00 \mathrm{m}\) of the string?

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.