6-18 할리데이 11판 솔루션 일반물리학

$$ \begin{cases} m&=110\ut{g}\\ S&=17\ut{m}\\ v_0&=5.0\ut{m/s}\\ g&=9.80665\ut{m/s^2} \end{cases} $$ $$2aS=v^2-{v_0}^2,$$ $$ \begin{aligned} \vec a&=\frac{0^2-{v_0}^2}{2S}\\ &=-\frac{{v_0}^2}{2S}\\ a&=\frac{25}{34}\ut{m/s^2} \end{aligned} $$ $$\ab{a}$$ $$ \begin{aligned} f&=ma\\ &=\frac{11}{136}\ut{N}\\ &\approx 0.08088235294117647\ut{N}\\ &\approx 0.081\ut{N}\\ &\approx 81\ut{mN}\\ \end{aligned} $$ $$\ab{b}$$ $$f=\mu F_N=\mu mg$$ $$ \begin{aligned} \mu&=\frac{ma}{mg}\\ &=\frac{a}{g}\\ &\approx 0.07497913330720062\\ &\approx 0.075\\ \end{aligned} $$