Đáp án:
\(\begin{array}{l}
9.C.3m/s\\
p = p'\\
\Rightarrow 0 = mv - m'v'\\
\Rightarrow v' = \dfrac{{mv}}{{m'}} = \dfrac{{100.15}}{{500}} = 3m/s\\
10.D. - 3,6kg.m/s\\
\Delta p = p' - p = m( - v') - mv = - mv - mv = - 2mv\\
= - 2.0,3.6 = - 3,6kg.m/s
\end{array}\)