7-29 할리데이 11판 솔루션 일반물리학

$$ \begin{cases} A&:(3.0,4.0)\ut{m}\\ F&=5.0\ut{N},\theta_F=100\degree\\ \end{cases} $$ $$W=\vec F \cdot \vec S,$$ $$ \begin{aligned} W&=(5\cos100\degree\i+5\sin100\degree) \cdot (3\i+4\j)\\ &=5\cos100\degree \cdot 3+5\sin100\degree\cdot4\\ &\approx 17.091432395240204\ut{J}\\ &\approx 17\ut{J}\\ \end{aligned} $$