11-26 할리데이 11판 솔루션 일반물리학

$$\begin{cases} m_A&=3.00\ut{kg}\\ \vec v_{Ai}&=-3.00\j\ut{m/s}\\ m_B&=4.00\ut{kg}\\ M&=m_A+m_B=7.00\ut{kg}\\ \vec v_{Bi}&=4.50\i\ut{m/s}\\ \vec r_P&=-0.500\i-0.100\j\ut{m}\\ \end{cases}$$ $$\Delta \Sigma \vec p=0,$$ $$\begin{aligned} \vec p_f&=\Sigma \vec p_i\\ &=m_A\vec v_{Ai}+m_B\vec v_{Bi}\\ \end{aligned}$$ $$\begin{aligned} \vec L_f&=\vec r\times\vec p_{f},\\ &=\vec r\times(\Sigma \vec p_i),\\ &=\vec r\times(m_A\vec v_{Ai}+m_B\vec v_{Bi})\\ &=6.30\k\ut{kg\cdot m^2/s}\\ \end{aligned}$$