Đáp án:
\(\begin{array}{l}
{v_1} = 36km/h\\
{v_2} = 24km/h
\end{array}\)
Giải thích các bước giải:
\(\begin{array}{l}
{t_1} = {t_2} = \frac{t}{2} = \frac{{1,5}}{2} = 0,75h\\
{t_1} = \frac{{{s_1}}}{{{v_1}}}\\
{t_2} = \frac{{{s_2}}}{{{v_2}}} = \frac{{{s_2}}}{{\frac{2}{3}{v_1}}}\\
{t_1} = {t_2}\\
\frac{{{s_1}}}{{{v_1}}} = \frac{{{s_2}}}{{\frac{2}{3}{v_1}}}\\
{s_1} = 1,5{s_2}\\
{s_1} + {s_2} = s = 45\\
\Rightarrow {s_1} = 27km\\
{v_1} = \frac{{{s_1}}}{{{t_1}}} = \frac{{27}}{{0,75}} = 36km/h\\
{v_2} = \frac{2}{3}{v_1} = \frac{2}{3}.36 = 24km/h
\end{array}\)