6-55 할리데이 11판 솔루션 일반물리학

$$ \begin{cases} m_1&=m=16\ut{kg}\\ m_2&=M=50\ut{kg}\\ \mu&=0.30\\ g&=9.80665\ut{m/s^2}\\ \end{cases} $$ $$\Sigma \vec F = m\vec a,$$ $$ \begin{cases} \Sigma F_{1x} &= m_1 a\\ \Sigma F_{1y} &= 0\\ \Sigma F_{2x} &= m_2 a\\ \Sigma F_{2y} &= 0\\ \end{cases} $$ $$ \begin{cases} m_1 a &= F-N_1\\ 0 &= \mu N_1-m_1g\\ m_2 a &= N_1\\ 0 &= N_2-\mu N_1-m_2g\\ \end{cases} $$ $$ \begin{aligned} F&=\frac{ m_1 \left(m_1+m_2\right)}{\mu m_2}g\\ &=\frac{352}{5}g\\ &=690.38816\ut{N}\\ &\approx 6.9\times10^2\ut{N}\\ \end{aligned} $$