Giải thích các bước giải:
Câu 11:
1. \(p = {m_1}{v_1} + {m_2}{v_2} = 38(kg.m/s)\)
2. \(p = - {m_1}{v_1} + {m_2}{v_2} = 22(kg.m/s)\)
3. \(P = \sqrt {{{({m_1}{v_1})}^2} + {{({m_2}{v_2})}^2}} = 31(kg.m/s)\)
4. \(P = \sqrt {{{({m_1}{v_1})}^2} + {{({m_2}{v_2})}^2} + 2{m_1}{v_1}.{m_2}{v_2}\cos 120} = 27(kg.m/s)\)
Câu 12:
1. \(\begin{array}{l}
{m_1}{v_1} = {m_1}{v_1}' + {m_2}{v_2}'\\
\Rightarrow {v_2}' = \frac{{{m_1}{v_1} - {m_1}{v_1}'}}{{{m_2}}} = \frac{{76}}{3}(cm/s)
\end{array}\)
2. \(\begin{array}{l}
{p^2} = {p_1}^2 + p_2^2 + 2{p_1}{p_2}cos120\\
\Rightarrow {p_2} = 9,34(kg.m/s)\\
\Rightarrow {v_2} = 31,13(cm/s)
\end{array}\)
