Find the frequency and wavelength of a 100 MeV gamma ray photon

In summary: In summary, the conversation discusses finding the frequency and wavelength of a 100 MeV gamma ray photon. The equations used involve the Planck constant, speed of light, and energy of the photon. The final solutions are a frequency of (2.47 x 10^22) Hz and a wavelength of (1.215 x 10^-14) meters. The conversation also mentions the importance of using consistent units when using these equations.
  • #1
2
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Homework Statement



Find the frequency and wavelength of a 100 MeV gamma ray photon

Homework Equations




100 MeV=1.602 X 10^-11

The Attempt at a Solution



I do not know how to do this. I am in a class for elementary teachers and we have to solve this problem.
 
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  • #2
Do you have any equations that relate wavelength to frequency?
 
  • #3
I do not know any.
 
  • #4
Well you should certainly have an equation for relating wavelength and frequency, the less obvious thing is relating the energy of a photon to the frequency/wavelength

You should also have an equation for that, it involves Planck's constant, h
 
  • #5
Wave length equals frequency times 340 meters per second...
 
  • #6
Wave length equals frequency times 340 meters per second...

Unfortunately that's the specific equation for sound waves, pretty much at sea level. The topic creator is dealing with electromagnetic waves
 
  • #7
The equation for frequency and wavelength is simply speed = wavelength * frequency
A gamma ray photon is a kind of light so you need the speed of light.

There is also an equation relating it energy, energy = h * frequency
where 'h' is a constant = 6.6 x 10 ^-34 Js

Remember that all you values must be in the same units ( metres, seconds, Joules) for these constant to work
 
  • #8
We're doing this in my A-level at school.

First find the frequency using, Energy (J)=Planck Constant (Js) X Frequency (Hz)
Or, E=hf.
The Planck Constant is (6.6 x 10^-34).
---------------------------------------------------
So:
(1.602 X 10^-11)J = (6.6 x 10^-34)Js X f

Or

(1.602 X 10^-11)J / (6.6 x 10^-34)Js = f

So the frequency is (2.47 X 10^22)Hz.
----------------------------------------------------
Speed (ms) = Frequency (Hz) X Wavelength (m)

So:

Speed of light-> (3.0 X 10^8)ms / (2.47 X 10^22)Hz = Wavelength (m)

=(1.215 X 10^-14)
 
  • #9
Welcome to PF, Dumbfish1.

FYI, we don't simply post solutions here when people ask for homework help. We give hints, and require that the asker make some attempt toward solving the problem first.

Since this question is from more than a year ago, I guess there was no harm done. You might want to familiarize yourself with the forum rules; simply scroll down to the section "Homework Help" here:

https://www.physicsforums.com/showthread.php?t=5374
 

1. What is the formula for calculating the frequency and wavelength of a 100 MeV gamma ray photon?

The formula for calculating the frequency and wavelength of a photon is:
Frequency = Energy / Planck's constant
Wavelength = Speed of light / Frequency

2. How do you convert MeV to Joules in this equation?

1 MeV (mega electron volt) is equal to 1.6 x 10^-13 Joules. Therefore, to convert MeV to Joules, simply multiply the energy in MeV by 1.6 x 10^-13.

3. What is the value of Planck's constant and the speed of light used in this calculation?

The value of Planck's constant (h) is 6.626 x 10^-34 Joule seconds, and the speed of light (c) is 3 x 10^8 meters per second. These values are used in the formula to calculate the frequency and wavelength of a photon.

4. Can you explain the concept of frequency and wavelength in relation to photons?

Frequency refers to the number of wave cycles that pass a given point in one second, while wavelength is the distance between two consecutive wave peaks. In the context of photons, frequency and wavelength are inversely proportional - as the frequency increases, the wavelength decreases, and vice versa.

5. How is the energy of a photon related to its frequency and wavelength?

The energy of a photon is directly proportional to its frequency, meaning that as the frequency increases, the energy also increases. This relationship is described by the equation: Energy = Planck's constant x Frequency. Wavelength is also related to energy, but inversely proportional - as the wavelength increases, the energy decreases.

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