# How much kinetic energy take the particles after the collision?

1. Nov 12, 2013

### skrat

1. The problem statement, all variables and given/known data
What is the minimum amount of kinetic energy of proton that hits another still proton so reaction $p+p\rightarrow p+n+\pi ^+$ is possible? How big part of the initial kinetic energy is used for kinetic energy of new particles?

2. Relevant equations

3. The attempt at a solution

$T_{min}=292MeV$

am.... I don't really understand the second question? I calculated the minimum kinetic energy with presumption that $p+n+\pi ^+$ will have no kinetic energy after the collision of protons... So... what exactly answers the second part of this problem?

2. Nov 15, 2013

### PAllen

You haven't mentioned conservation of momentum.

3. Nov 16, 2013

### PAllen

Also, consider the difference between how the collision looks in the COM frame vs. the lab frame. I assume the last question is being asked about the lab frame.