5-53 할리데이 11판 솔루션 일반물리학

$$ \begin{cases} m_h&=15000\ut{kg}\\ m_t&=4500\ut{kg}\\ a&=1.4\ut{m/s^2}\\ g&=9.80665\ut{m/s^2} \end{cases} $$ $$\Sigma \vec F = m\vec a,$$ $$ \begin{cases} \Sigma F_h &= m_h a\\ \Sigma F_t &= m_t a\\ \end{cases} $$ $$ \begin{cases} F-m_hg-T &= m_h a\\ T-m_tg &= m_t a\\ \end{cases} $$ $$\ab{a}$$ $$ \begin{aligned} F&=(m_h+m_t)(g+a)\\ &=3900(7+5g)\\ &=218529.675\ut{N}\\ &\approx 2.2\times10^5\ut{N}\\ \end{aligned} $$ $$\ab{b}$$ $$ \begin{aligned} T&=m_t(g+a)\\ &=900(7+5g)\\ &=50429.925\ut{N}\\ &\approx 5.0\times10^4\ut{N}\\ \end{aligned} $$