## Heisenberg and Wavelength

$\Delta p \Delta x\geq \frac{h}{4\pi }$

ThomasLai1D
Posts: 61
Joined: Fri Sep 28, 2018 12:17 am

### Heisenberg and Wavelength

Hi,

I am just going over the last test, and one of the conceptual questions asked "How does the change in uncertainty in momentum affect the uncertainty in its wavelength?" I answered that there would be no impact because the Heisenberg principle does not relate momentum and wavelength, but it was incorrect. Would someone provide the correct answer?

Thanks

WilliamNguyen_4L
Posts: 65
Joined: Fri Sep 28, 2018 12:28 am

### Re: Heisenberg and Wavelength

This has to do with the equation wavelength=h/p. Since momentum is the denominator in that equation there is an inverse relationship between momentum and wavelength. Therefore if the uncertainty of the momentum increases then the uncertainty of wavelength decreases and vice versa.

caseygilles 1E
Posts: 73
Joined: Fri Sep 28, 2018 12:18 am

### Re: Heisenberg and Wavelength

The question is trying to get us to mention that the more we know about one, the less we know about the other. So, if we know the uncertainty in position is a very specific discrete value, we will know less about the value in the uncertainty of momentum.

Grace Diaz 3F
Posts: 30
Joined: Fri Sep 28, 2018 12:24 am

### Re: Heisenberg and Wavelength

momentum does affect wavelength, since they have a reciprocal relationship. That is the concept behind de Broglie's equation (wavelength= plank's constant/momentum)

Phil Timoteo 1K
Posts: 101
Joined: Fri Apr 06, 2018 11:05 am

### Re: Heisenberg and Wavelength

It does because wavelength is equal to h/momentum. So they are inversely related the higher the momentum the smaller the wavelength and vice versa.

705152867
Posts: 28
Joined: Fri Sep 28, 2018 12:18 am

### Re: Heisenberg and Wavelength

wavelength=planck's constant/momentum, so wavelength and momentum do affect each other. However, I believe the question is looking for the answer explaining how the less we know about uncertainty in momentum, the less we know about uncertainty in position and vice-versa.

DavidEcheverri3J
Posts: 36
Joined: Fri Sep 28, 2018 12:26 am

### Re: Heisenberg and Wavelength

Hey guys, new interesting fact... the kilogram is being redefined! https://youtu.be/c_e1wITe_ig

705022748
Posts: 26
Joined: Fri Sep 28, 2018 12:25 am

### Re: Heisenberg and Wavelength

momentum and wavelength directly affect each other.

Michael_Navarro_1H
Posts: 29
Joined: Fri Sep 28, 2018 12:17 am

### Re: Heisenberg and Wavelength

If a question like this were to come up on the final, I would find an equation where each variable is included and see if there is a way to relate them together that would assist you in answering the question.

Nina Do 4L
Posts: 61
Joined: Fri Sep 28, 2018 12:27 am

### Re: Heisenberg and Wavelength

I wrote something along the lines of they are inversely proportional to one another and that it is impossible to know both momentum and position at the same time and got credit for it. Hope that helps!

Lopez_Melissa-Dis4E
Posts: 66
Joined: Fri Sep 28, 2018 12:20 am

### Re: Heisenberg and Wavelength

Because momentum and wavelength are inverses of one another, if you know the precise value for one then you don't know the value of the other. (vice versa) That is why it is named the Heisenburg Uncertainty Principle.

uhedlund
Posts: 38
Joined: Wed Nov 15, 2017 3:03 am

### Re: Heisenberg and Wavelength

Because wavelength=planck's constant/momentum, they have an inverse relationship. As momentum increases, wavelength decreases.