6-64 할리데이 11판 솔루션 일반물리학

$$ \begin{cases} mg&=220\ut{N}\\ \mu_s&=0.41\\ \mu_k&=0.32\\ g&=9.80665\ut{m/s^2} \end{cases} $$ $$\ab{a}$$ $$ \begin{aligned} f_{s\max}&=\mu_s mg\\ &=\frac{451}{5}\ut{N}\\ &=90.2\ut{N}\\ &\approx 90\ut{N}\\ \end{aligned} $$ $$\ab{b}$$ $$ \begin{aligned} f_k&=\mu_k mg\\ &=\frac{352}{5}\ut{N}\\ &=70.4\ut{N}\\ &\approx 70\ut{N}\\ \end{aligned} $$ $$\ab{c}$$ $$\Sigma \vec F = m\vec a,$$ $$ \begin{aligned} a&=\frac{\Sigma F}{m}\\ &=\frac{f_{s\max}-f_k}{m}\\ &=\frac{9g}{100}\\ &= 0.8825985\ut{m/s^2}\\ &\approx 0.88\ut{m/s^2}\\ \end{aligned} $$