9-60 할리데이 11판 솔루션 일반물리학

$$ \begin{cases} v_i&=2.0\ut{m/s}\\ m&=4.0\ut{kg}\\ \Delta \Sigma \KE &=16\ut{J}\\ \end{cases} $$ $$ \begin{cases} \Delta \Sigma \vec p&=0,\\ \Delta \Sigma \KE &=16\ut{J}\\ \end{cases} $$ $$ \begin{cases} 2mv_i&=mv_A+mv_B\\ \frac{1}{2}(2m) {v_i}^2+16&=\frac{1}{2}m {v_A}^2+\frac{1}{2}m {v_B}^2 \end{cases} $$ $$ \begin{cases} v_A&=v_i+\frac{4}{\sqrt m}\\ v_B&=v_i-\frac{4}{\sqrt m}\\ \end{cases} $$ $$ \begin{cases} v_A&=v_i+\frac{4}{\sqrt m}\\ v_B&=v_i-\frac{4}{\sqrt m}\\ \end{cases} $$ $$\ab{a}$$ $$ \begin{aligned} v_B&=v_i-\frac{4}{\sqrt m}\\ &=0\\ &=0.0\\ \end{aligned} $$ $$\ab{b}$$ $$ \begin{aligned} v_A&=v_i+\frac{4}{\sqrt m}\\ &=4\ut{m/s}\\ &=4.0\ut{m/s}\\ \end{aligned} $$