Answer
The velocity of the center of mass of the system is $37.4~m/s$
Work Step by Step
We can find the velocity of the center of mass of the system:
$v_{com} = \frac{m_1~v_1+m_2~v_2+m_3~v_3}{m_1+m_2+m_3}$
$v_{com} = \frac{(3.0~kg)(290~m/s)+(5.0~kg)(-120~m/s)+(2.0~kg)(52~m/s)}{3.0~kg+5.0~kg+2.0~kg}$
$v_{com} = 37.4~m/s$
The velocity of the center of mass of the system is $37.4~m/s$.
