kinetic energy/momentum conservation (rest mass energy)

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IndyZX

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when an atom shoots off an alpha particle during alpha decay, is kinetic energy or momentum conserved?

i say neither is conserved, what do you think?

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I think it would be:
kinetic energy: no, because mass is being converted to kinetic energy
momentum: yes, because the nucleus will recoil in response to the alpha particle ejection.
 
doesnt total mass increase? some of the weak nuclear force is coverted to mass i thought...
 
liverotcod said:
I think it would be:
kinetic energy: no, because mass is being converted to kinetic energy
momentum: yes, because the nucleus will recoil in response to the alpha particle ejection.

Yes, I believe that this is correct.
 
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I'm not 100% clear... but this site is helpful. There is mass lost in alpha decay, probably because of the decrease in potential energy in the parent nucleus after the decay.
 
Mass is probably lost due to speed of these nuclear particles (dilation factor effect), especially electrons--decrease in potential energy which follows from increase in KE of the moving particles.

I think I just rambled nonsense here :oops:
 
Everyone's got the right answer here (KE not conserved, because a massive particle is ejected; momentum conserved). Just wanted to point out: momentum is always conserved, as long as you're considering a closed system.
 
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