wavelength

[adrakdavra]

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what does larger wavelength means in term of the distance between nodes and speed?

True or False: Longer sound wavelengths travel at faster speeds than shorter wavelengths.?

 

[adrakdavra]

True or False: Longer sound wavelengths travel at faster speeds than shorter wavelengths.?

 

[gwjib04]

If they are sound waves don't they travel at the speed of sound?

Nodes occur at the x-axis. Longer wavelength will have greater distances between its intersections with the x-axis.

 

[Gauss44]

True or False: Longer sound wavelengths travel at faster speeds than shorter wavelengths.?

It depends on the frequency.

velocity = frequency times wavelength

 

[gwjib04]

It depends on the frequency.

velocity = frequency times wavelength

Not true, wavelength and frequency are related for a fixed velocity.

Thanks to Milski for this:

v=fλ gives you the relation between the frequency and the wavelength for a given speed of propagation of the wave. The speed of the wave is property of the media and does not depend on the frequency/wavelength. Trying to change the wavelength will result in a change of the frequency or vice versa when the media stays the same.

 

[mauroz]

The speed of sound stays constant in a given medium just as the speed of light stays constant in a medium or vacuum. Switching mediums is the only way to change the speed of these waves. So the speed remains the same, frequency and wavelength are inversely related.

 

[Laureatebarrel]

The speed of sound stays constant in a given medium just as the speed of light stays constant in a medium or vacuum. Switching mediums is the only way to change the speed of these waves. So the speed remains the same, frequency and wavelength are inversely related.

Wrong, sound wave and light wave are different! Sound wave is longitudinal wave while light wave is transverse. Sound wave depends only on the medium, so the denser the medium, the faster sound wave travels. Light wave depends on both the medium and the frequency of the wave. In a medium with higher refraction index, light wave travels slower than vacuum. The higher the frequency, the slower that wave travels in that medium. Thus red light will travel faster than blue light in water.
Speed of light in medium = speed of light in vacuum/refraction index

 

[mauroz]

Wrong, sound wave and light wave are different! Sound wave is longitudinal wave while light wave is transverse. Sound wave depends only on the medium, so the denser the medium, the faster sound wave travels. Light wave depends on both the medium and the frequency of the wave. In a medium with higher refraction index, light wave travels slower than vacuum. The higher the frequency, the slower that wave travels in that medium. Thus red light will travel faster than blue light in water.
Speed of light in medium = speed of light in vacuum/refraction index

I didn't say they were the same, I said that the speed that the waves travel stays constant as long as the medium in which they are in does not change. I simply compared this constant velocity to light because light waves tend to be more intuitive. And yes they will react differently when changing mediums because of the nature of the waves.

 

[adrakdavra]

True or False: Longer sound wavelengths travel at faster speeds in water than shorter wavelengths in air?

 

[milski]

True. The wavelengths don't matter, just the media.

 

[adrakdavra]

Sound waves, on the other hand, speed up underwater. So by the same logic of density and pressure, their wavelength increases when they hit the water (since frequency remains constant).
but my question is about the shape of the wave itself in term of the distance between nodes.
I understand that faster sound wave in water will have larger wavelength, however, does larger wavelength means longer lamda ( the distance is longer between the nodes) does than mean the number of wavelengths over a distance (d) is less. when i see a lot short wavelengths I started thinking they are faster because there are a lot of them over the same distance, but then I think about it further, it will take the larger amount of shortwaves a longer time to pass the distance.
Is it like walking, if I make a longer foot steps, I will be moving faster, whereas, If I make shorter steps then I am walking slower, assuming that my foot is moving at the same speed in the longer and shorter step. I hope my questions is clear.

 

[sdm33]

If your foot step is "one wavelength," then it might seem like increasing your foot step will increase your speed, since you'll be taking bigger steps. However, you always have to consider your frequency, or how often you take a step. For instance, let's assume your step is 2 feet long, and my step is only 1 foot long. It might seem like you'll travel faster than me. But, what if I take 3 steps every second, and you only take 1. Each second, I move 3 feet, and you only move 2! Clearly, I'd be moving faster. So, the velocity of a wave is determined in part by the wavelength, but we must also consider the frequency (the number of footsteps/waves per second) before we can know the wave's velocity. 🙂