2-27 할리데이 11판 솔루션 일반물리학

$$ \begin{cases} t&=1.8\ut{s}\\ v_1&=1400\ut{km/h}=\cfrac{3500}{9}\ut{m/s}\\ g&=9.80665\ut{m/s^2} \end{cases} $$ $$\ab{a}$$ $$ \begin{aligned} v&=v_0+at,\\ \(\frac{3500}{9}\)&=(0)+a(1.8)\\ \end{aligned} $$ $$ \begin{aligned} a&=\frac{17500}{81}\ut{m/s^2}\\ &=\frac{50000000}{2269539}g\\ &\approx22.03090583594289g\\ &\approx22g\\ \end{aligned} $$ $$\ab{b}$$ $$ \begin{aligned} S&=\frac{1}{2}(v+v_0)t,\\ &=\frac{1}{2}\bra{\(\frac{3500}{9}\)+0}(1.8)\\ &=350\ut{m}\\ &=3.5\times10^2\ut{m} \end{aligned} $$