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-   -   Ratio kinetic energy of alpha particle / kinetic energy of proton (http://www.physicsforums.com/showthread.php?t=308892)

 385sk117 Apr21-09 03:17 PM

Ratio kinetic energy of alpha particle / kinetic energy of proton

1. The problem statement, all variables and given/known data
A photon and alpha particle are accelerated from rest through the same potential difference.
After acceleration what is the ratio kinetic energy of alpha particle / kinetic energy of proton?

2. Relevant equations
I guess I have to use eV = 1/2mv^2

3. The attempt at a solution
I dont know what value have to be used in place of e in equation eV = 1/2mv^2
the mass of alpha particle is approximately 4 times of photon and that's all i know
I think there is something to do with the velocity of alpha particle and photon but i'm stucked can not think of anything..

 ImAnEngineer Apr21-09 03:24 PM

Re: Ratio kinetic energy of alpha particle / kinetic energy of proton

An alfa particle has two protons, so that's twice the charge of one proton.

 385sk117 Apr22-09 12:24 AM

Re: Ratio kinetic energy of alpha particle / kinetic energy of proton

Thanks a lot! So i didnt have to know the exact charges but the ratio

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