11-33 할리데이 11판 솔루션 일반물리학

$$\begin{cases} m&=0.25\ut{kg}\\ \vec r&=2.0i-2.0\k\ut{m}\\ \vec v&=-5.0\i+8.0\k\ut{m/s}\\ \vec F&=4.0\j\ut{N}\\ \end{cases}$$ $$\ab{a}$$ $$\begin{aligned} \vec L&=\vec r\times m\vec v\\ &=-1.5\j\ut{kg\cdot m^2/s} \end{aligned}$$ $$\ab{b}$$ $$\begin{aligned} \vec \tau&=\vec r\times \vec F\\ &=8.0\i+8.0\k\ut{N\cdot m} \end{aligned}$$