3-16 할리데이 11판 솔루션 일반물리학

$$ \begin{cases} \vec d&=5.70\ut{m}\j\\ \end{cases} $$ $$\ab{a},\ab{b}$$ $$ \begin{aligned} 4.00\vec d&=4\times5.7\ut{m}\j\\ &=22.8\ut{m}\j\\ \end{aligned} $$ $$\ab{a}$$ $$22.8\ut{m}$$ $$\ab{b}$$ $$\text{North}$$ $$\ab{c},\ab{d}$$ $$ \begin{aligned} -5.00\vec d&=-5\times5.7\ut{m}\j\\ &=-28.5\ut{m}\j\\ \end{aligned} $$ $$\ab{a}$$ $$28.5\ut{m}$$ $$\ab{b}$$ $$\text{South}$$