A shot of mass m is fired from a gun of mass M with velocity u relative to the gun. The actual velocities of the shot and gun are:
1
\(\frac{{Mu}}{{M + m}},\frac{{mu}}{{M + m}}\)
2
\(\frac{{(M+m)u}}{{M-m}},\frac{{(M-m)u}}{{M+m}}\)
3
\(\frac{{mu}}{{M+m}},\frac{{Mu}}{{M+u}}\)
4
\(\frac{{(M+m)u}}{{M-m}},\frac{{(M+m)u}}{{M+m}}\)