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

A disc of mass m is moving horizontally to the right with speed v on a table with neglibible friction when it collides with a second disc of mass 2m. The second disc is moving horizontally to the right with speed v/2 at the moment of impact. The two disc stick together upon impact. The speed of the body immediately after the collision is:

A)v/3

B)v/2

C)2v/3

D)3v/2

E)2V

2. Relevant equations

p = mv (that wasn't given, but that's the equation I used)

3. The attempt at a solution

mv = mv + 2mv/2

m(v) = m(v+2v/2)

v= v+2v/2

v= 2v/2 + 2v/2

for the final answer, I got: v= 2V, according to my answer sheet, the correct answer is 2v/3. I can't seem to figure out what I'm doing wrong. Please help.

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# Homework Help: Composite Body Momentum

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