(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A lambda particle decays into a proton and a pion, and it is observed that the proton is at left at rest. A. What is the energy of the pion? B. What was the energy of the original lambda? (The masses involved are m[tex]_{}\lambda[/tex] = 1116, m[tex]_{}p[/tex] = 938, and m[tex]_{}\pi[/tex] = 140, all in MeV/c^2

2. Relevant equations

E=[tex]\gamma[/tex](m)(c^2) P=[tex]\gamma[/tex](m)(u) E^2=(pc)^2+(mc^2)^2

When u=0, E=mc^2

3. The attempt at a solution

I realize that this is largely a conservation of momentum and energy problem. The proton is at rest, so it has zero momentum. This also means that P[tex]\lambda[/tex]=P[tex]\pi[/tex]

[tex]\gamma[/tex](lambda)*m(lambda)*c^2=[tex]\gamma[/tex](pi)*m(pi)*c^2+m(p)c^2

I have plugged in and tried to solve it down along with the momentum, but no matter what I do I can't do the algrebra. Any help is greatly appreciated.

And the answers are 184 MeV and 1122 MeV, respectively

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# Homework Help: Relativity: Conversion of Mass and Energy

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