# Homework Help: A Probelm To far

1. Feb 28, 2005

### siresam88

A Problem To far !!!

6a) Calculate the wavelength of a gamma - ray photon which has an energy of 1.6 *10-15

6b) An x ray is generated which has the same energy as the gamma ray described in part(a) compare these two photons of thier:

(i) Speed of transmission in a vacuum.

(ii) Ability to penetrate a given material.

If somebody could help me with these questions i would be delighted

Last edited: Feb 28, 2005
2. Feb 28, 2005

### yay_goobers2112

I'm not sure I understand the question completely, but:
Energy of the wave is equal to plank's constant by the frequency,
E=hf
And the velocity is equal to the wavelength by the frequency
V=fλ
So you get:λ=(Vh)/E
If you're in a vacuum, V=c, the speed of light in a vacuum, otherwise you need a ratio of refraction.
However, when this is computed with the 1.6*10^-15 J (Joules I'm assuming), you get about 1.2*10^-10 m, which is in the X-ray part of the electromagnetic spectrum.

3. Feb 28, 2005

### kevinalm

Part b is a trick question. It's supposed to illustrate that x and gamma are both photons, and if the energy of the two photons is identical there no difference between them. The terms xray and gamma ray are somewhat interchangable. We tend to call the low energy end x and the high gamma, but there is a lot of overlap. The source of the radiation influences what we call it also. For example, we tend to call photons from nuclear decay gamma and from electonic equipment xray (like your dentist's xray machine)

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