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

Two identical masses m are initially at rest, separated by a distance x. A constant force F

accelerates one particle until it collides and combines with the other. What is the mass of

the resulting particle?

2. Relevant equations

F = gamma^{3}mv

3. The attempt at a solution

Presumably you must calculate conservation of energy (which is whatever the energy is of the single mass moving must equal that of them combined).

Then I guess you need to calculate conservation of momentum, which should also be easy especially since it's in one direction after all.

Lastly you could just plug it into the equation E^{2}= p^{2}c^{2}+ (2m)^{2}c^{2}

The thing I don't understand is what energy/momentum the mass has pre-impact. We've never done a problem with the equation I gave before so I'm not sure if it's needed, but in any case I attempted solving with that equation for F and then multiplying by t to get the momentum and got c^{3}*m*a*t/(c^{2}- (at)^{2})^{3/2}which seemed way too complicated for so early. I would also just do energy of the big mass = gamma*m*c^2+mc^2 and that would give me the part for E^2 and i w ould have all necessary parts... But I don't know if my original thing is right at all :/

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# Homework Help: Special Relativity Question

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