2-37 할리데이 11판 솔루션 일반물리학

$$\begin{cases} t_s&=7.3\ut{s}\\ t_{ns}&=24.0\ut{s}\\ \end{cases}$$ $$\ab{a}$$ $$\begin{aligned} \frac{v_s}{v_{ns}}&=\frac{\(\dfrac{S}{t_s}\)}{\(\dfrac{S}{t_{ns}}\)}\\ &=\frac{t_{ns}}{t_s}\\ &=\frac{24}{7.3}\\ &=\frac{240}{73}\\ \end{aligned}$$ $$\begin{aligned} v_s : v_{ns}=240:73 \end{aligned}$$ $$\ab{b}$$ $$v_s : v_{ns}=240:73,$$ $$\begin{aligned} v_{ns}&=\frac{73}{240}v_s \end{aligned}$$ $$\begin{aligned} \Delta t&=t_{ns2}-t_{s2}\\ &=\frac{S}{v_{ns}}-\frac{S}{v_{s}}\\ &=\frac{S}{\frac{73}{240}v_s}-\frac{S}{v_{s}}\\ &=\frac{S}{v_s}\(\frac{1}{\frac{73}{240}}-1\)\\ &=\frac{1.5}{v_s}\(\frac{1}{\frac{73}{240}}-1\)\\ &=\frac{501}{146v_s}\\ &\approx 3.431506849315069{v_s}^{-1}\\ &\approx 3.4{v_s}^{-1}\\ \end{aligned}$$