2-32 할리데이 11판 솔루션 일반물리학

$$ \begin{cases} \Delta x&=65.0\ut{m}\\ \Delta t&=6.00\ut{s}\\ v_2&=15.0\ut{m/s} \end{cases} $$ $$\ab{a}$$ $$ \begin{aligned} S&=\frac{1}{2}(v+v_0)t,\\ 65&=\frac{1}{2}(15+v_1)(6)\\ \end{aligned} $$ $$ \begin{aligned} v_1&=\frac{20}{3}\ut{m/s}\\ &\approx6.666666666666667\ut{m/s}\\ &\approx6.67\ut{m/s}\\ \end{aligned} $$ $$\ab{b}$$ $$ \begin{aligned} S&=vt-\frac{1}{2}at^2,\\ 65&=(15)(6)-\frac{1}{2}a(6)^2\\ \end{aligned} $$ $$ \begin{aligned} a&=\frac{25}{18}\ut{m/s^2}\\ &\approx 1.388888888888889\ut{m/s^2}\\ &\approx 1.39\ut{m/s^2}\\ \end{aligned} $$ $$\ab{c}$$ $$ \begin{aligned} 2aS&=v^2-v_0^2,\\ 2\(\frac{25}{18}\)S&=\(\frac{20}{3}\)^2-{0}^2\\ S &=16\ut{m}\\ &=16.0\ut{m} \end{aligned} $$