11판/3. 벡터

3-15 할리데이 11판 솔루션 일반물리학

짱세디럭스 2024. 1. 22. 20:56
$$ \begin{cases} r_1&=310\ut{m}, \theta_1=25\degree\\ \vec r_1 &= 310\cos25\ut{m}\degree\i+310\sin25\degree\ut{m}\j\\ \vec r_2 &= 205\ut{m}\i \end{cases} $$ $$ \begin{aligned} \Sigma \vec r &= (310\cos25\degree+205)\i+310\sin25\degree\j\\ \end{aligned} $$ $$\ab{a}$$ $$ \begin{aligned} \abs{\Sigma \vec r}&=\sqrt{96100 \sin ^225\degree+\(310 \cos 25\degree+205\)^2}\ut{m}\\ &\approx 503.3057914750814\ut{m}\\ &\approx 5.0\times10\ut{m}\\ \end{aligned} $$ $$\ab{b}$$ $$ \begin{aligned} \theta&=\tan^{-1}\frac{310\sin25\degree}{310\cos25\degree+205}\\ &\approx 0.2633352952887049\ut{rad}\\ &\approx 0.26\ut{rad}\\ \end{aligned} $$ $$\ab{c}$$ $$ \begin{aligned} r_1+r_2&= 310+205\ut{m}\\ &= 515\ut{m} \end{aligned} $$ $$\ab{d}$$ $$\abs{\Sigma \vec r}