Wave problem It's been driving my crazy for last hour

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In summary: A, k, and W respectively.In summary, the conversation is about a homework problem involving wave motion and finding the velocity of propagation for a transverse wave on a string. The first part involves using the wave function y(x,t) = Acos2pi(kx-wt) to find the velocity, while the second part involves finding the values of A, k, and W for a standing wave with given amplitude, period, and speed. The correct values are 4.92×10−3, 15.5, and 1720 for A, k, and W respectively.
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asd1249jf
Wave problem! It's been driving my crazy for last hour!

Homework Statement


A)
Wave motion is characterized by two velocities: the velocity with which the wave moves in the medium (e.g., air or a string) and the velocity of the medium (the air or the string itself).

Consider a transverse wave traveling in a string. The mathematical form of the wave is y(x,t) = Acos2pi(kx-wt)

Find the velocity of propagation Vp of this wave.
Express the velocity of propagation in terms of some or all of the variables A, k, and W.

B)Two traveling waves move on a string that has a fixed end at . They are identical, except for opposite velocities. Each has an amplitude of 2.46 mm, a period of 3.65 ms, and a speed of 111 m/s.

The wave function of the resulting standing wave has the form y(x,t)=Asin(kx)sin(wt). Give the values of A, k, and W. Use meters (m) for A, inverse meters (1/m) for k, and inverse seconds (1/s) for W.




Homework Equations


A)
I believe I should use y(x,t) = Acos2pi(kx-wt)
B)
A is given
W=2(pi)f where f = 1/T
K = w/v

The Attempt at a Solution



A)
Ok so to find the velocity, we take the partial derivative and get
dy/dt = wAsin[kx-wt]

And I thought that was the answer but apparently it wasn't.

What is the velocity of propagation anyways? Maybe that's where I need to start.

B)
This one, I thought I had it right but apparently, Mastering Physics has been telling me its not.

Amplitude's given, so just convert 2.46mm to meters.

W(Omega) can be simply found by the equation w = 2pi/T

And since velocity is given, we can just plug that value in into k = w/v and find the wave number.

I got 2.46*10^-3 as Amplitude, 1720 for W and 15.5 for k and the program's telling me its wrong.

Am I tackling the problem wrong?

Any help would be deeply appriciated
 
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Bumpppppppppp
 
  • #3


Can anyone help with this? I too have been trying to figure it out, only part B.
 
  • #4


For the record, the answer turned out to be:

4.92×10−3, 15.5, 1720
 

Related to Wave problem It's been driving my crazy for last hour

1. What is a wave?

A wave is a disturbance or oscillation that travels through space or matter, transferring energy from one point to another without causing any permanent displacement of the medium.

2. What causes waves?

Waves can be caused by a variety of sources, including vibrations, wind, earthquakes, or even human activity such as sound waves from speaking or music.

3. What are the types of waves?

There are two main categories of waves: mechanical and electromagnetic. Mechanical waves require a medium to travel through, such as water or air, while electromagnetic waves do not require a medium and can travel through vacuum. Examples of mechanical waves include sound waves, water waves, and seismic waves. Examples of electromagnetic waves include light, radio waves, and X-rays.

4. What are the properties of waves?

Waves have several key properties, including amplitude, wavelength, frequency, and speed. The amplitude is the maximum displacement of the wave from its rest position, while the wavelength is the distance between two consecutive crests or troughs of a wave. Frequency is the number of complete waves that pass a point in a certain amount of time, and speed is the distance a wave travels per unit time.

5. How do we measure waves?

Waves can be measured in different ways depending on the type of wave. For example, the amplitude of a sound wave can be measured in decibels, while the wavelength of an electromagnetic wave can be measured in nanometers. The frequency of a wave is measured in hertz (Hz), and the speed of a wave is measured in meters per second (m/s).

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