9-37 할리데이 11판 솔루션 일반물리학

$$\begin{cases} m_L&=1.00\ut{kg}\\ m_R&=0.500\ut{kg}\\ \end{cases}$$ $$\Delta \Sigma \vec p=0,$$ $$m_Lv_L+m_Rv_R=0$$ $$\ab{a}$$ $$v_L=-1.20\ut{m/s},$$ $$\begin{aligned} v_R&=-\frac{m_L}{m_R}v_L\\ &=\frac{12}{5}\ut{m/s} \end{aligned}$$ $$\begin{aligned} S&=vt\\ &=\frac{48}{25}\ut{m}\\ &=1.92\ut{m} \end{aligned}$$ $$\ab{b}$$ $$v_{L\larr R}=-1.20\ut{m/s},$$ $$\begin{cases} m_Lv_L+m_Rv_R=0\\ v_{L\larr R}=v_L-v_R \end{cases}$$ $$\begin{aligned} v_L&=-\frac{m_R}{m_L-m_R}v_{L\larr R}\\ &=\frac{6}{5}\ut{m/s}\\ \end{aligned}$$ $$\begin{aligned} S&=vt\\ &=\frac{24}{25}\ut{m}\\ &=0.96\ut{m} \end{aligned}$$