## College Physics (4th Edition)

$p = 3.0~kg~m/s~~$ to the north
Let north be the positive direction. We can find the total momentum of the system: $p = m_1v_1+m_2v_2+m_3v_3$ $p = (3.0~kg)(3.0~m/s)+(4.0~kg)(-5.0~m/s)+(7.0~kg)(2.0~m/s)$ $p = 3.0~kg~m/s~~$ to the north