There's something in my theoretical mechanics handbook that i don't quite understand. Say you have an observer in a labratory watching 2 particles, one of wich is in a state of rest (m_2) and the other one (m1) is moving towards it.(adsbygoogle = window.adsbygoogle || []).push({});

the placevector of the center of mass of the system is

[tex] R = \frac{m_{1}.R_{10}+m_{2}.R_{20}}{m_{1}+m_{2}} $ [/tex]

wich moves with a speed

[tex] V = \frac{m_{1}.v_{10}}{m_{1}+m_{2}} = \frac{p_{10}}{m_{1}+m_{2}}$ [/tex]

v_10 and R_10 and R_20 seen by the labratory observer, say you have an observer at the centre of mass of the system, he observes the particles with speeds v_1 and v_2

for the observer at the centre of mass before the particles collide the impules p_1 and p_2 are the same but in oppsing directions. Now my handbook states that

[tex] p_{1}=p{2} = m_{2}.V = \frac{m_{2}.p_{10}}{m{1}+m{2}} [/tex]

wich i don't fully understand

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# Homework Help: Question on collisions

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