5-57 할리데이 11판 솔루션 일반물리학

$$ \begin{cases} m&=9.11\times10^{-31}\ut{kg}\\ S&=1.5\ut{cm}\\ v&=6.0\times10^6\ut{m/s}\\ g&=9.80665\ut{m/s^2} \end{cases} $$ $$\ab{a}$$ $$2aS=v^2-{v_0}^2,$$ $$ \begin{aligned} a&=\frac{v^2-{0}^2}{2S}\\ &=\frac{v^2}{2S} \end{aligned} $$ $$ \begin{aligned} F&=ma\\ &=\frac{mv^2}{2S}\\ &=1.0932\times10^{-15}\ut{N}\\ &\approx 1.1\times10^{-15}\ut{N}\\ &\approx 1.1\ut{fN} \end{aligned} $$ $$\ab{b}$$ $$ \begin{aligned} mg&=8.93385815\times10^{-30}\ut{N}\\ &\approx 8.93\times10^{-30}\ut{N}\\ &\approx 8.93\ut{qN}\\ \end{aligned} $$