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:
p = mv (that wasn't given, but that's the equation I used)
The Attempt at a Solution
mv = mv + 2mv/2
m(v) = m(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.