What is the Equation for Momentum in a Rifle Firing a Bullet?

[blackout85]

A rifle of mass M is intially at rest but free to recoil. It fires a bullet of mass m and velocity v (relative to the ground). After firing, the velocity of the rifle (relative to the ground) is:

P= m2V2 -m1v1
P= M(v-0) - m(v-0)
M(V-0) = m(V-0)
V-0= mv/M
V= -mv/M
is that right

 

[radou]

Yes, it is. Btw, you can post similar questions into the same thread next time.