Calculate wavelength of electron

In summary, the conversation revolves around a problem involving calculating the wavelength of an electron with a given speed, using the equation lambda=h/p. The poster initially gets a different answer than the one provided by the book, but is then reminded to take into account relativistic effects by using the equation lambda=h/γp, where γ is a factor involving the velocity of the electron. The term "momentum accounting for relativistic effects" is also mentioned in the conversation.
  • #1
okgo
61
0

Homework Statement



http://www.screencast.com/users/trinhn812/folders/Jing/media/9582a1aa-b21a-4e50-8774-b60866a7d666

Homework Equations



lambda=h/p

The Attempt at a Solution


So I got 4.04E-12 m but the book says the answer is 3.23pm

I'm not sure where I'm wrong
 
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  • #2
The speed of the electron is 0.6c, so you need to to use

λ=h/γp where γ = 1/√(1-(v/c)2)
 
  • #3
Thanks. So in addition to time dilation and length contraction, is this what you call momentum dilation?
 
  • #4
okgo said:
Thanks. So in addition to time dilation and length contraction, is this what you call momentum dilation?

Not sure if that is what it is called, but I call it momentum accounting for relativistic effects.
 
  • #5
.

First, let's define the variables:
- lambda is the wavelength of the electron
- h is Planck's constant (6.626 x 10^-34 m^2 kg/s)
- p is the momentum of the electron

To calculate the wavelength of the electron, we need to know the momentum. From the image provided, we can see that the momentum is 3.25 x 10^-24 kg m/s.

Now, let's plug in the values into the equation:
lambda = (6.626 x 10^-34 m^2 kg/s) / (3.25 x 10^-24 kg m/s)
= 2.04 x 10^-10 m

This result is in meters, but the book answer is in picometers (pm). To convert meters to picometers, we need to multiply by 10^12.
Therefore, the final answer is 2.04 x 10^-10 m x 10^12 = 2.04 x 10^2 pm = 204 pm.

So, the book answer of 3.23 pm is incorrect. The correct answer is 204 pm.
 

1. How do you calculate the wavelength of an electron?

The wavelength of an electron can be calculated using the de Broglie equation, which is λ = h/mv, where λ is the wavelength, h is Planck's constant, m is the mass of the electron, and v is the velocity of the electron.

2. What is the unit of measurement for the wavelength of an electron?

The unit of measurement for the wavelength of an electron is meters (m).

3. Can the wavelength of an electron be measured directly?

No, the wavelength of an electron cannot be measured directly. It can only be calculated using the de Broglie equation or indirectly measured in experiments such as the double-slit experiment.

4. What is the typical wavelength of an electron?

The typical wavelength of an electron is very small, around 10^-10 meters, due to its small mass and high velocity.

5. How does the wavelength of an electron compare to other particles?

The wavelength of an electron is much shorter than other particles such as protons or neutrons due to its smaller mass. However, it is longer than the wavelength of photons, which have no mass.

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