Đáp án:
\({v_c} = 15\left( {m/s} \right)\)
\(AB = 108000\left( m \right)\)
Giải thích các bước giải:
ta có \(\left\{ \begin{array}{l}
{t_{AB}} = 1h30p = 5400s\\
{t_{BA}} =10800s\\
{v_n} = 5m/s
\end{array} \right.\)
\(\begin{array}{l}
{v_{xuoi}} = {v_c} + {v_n} = \frac{{AB}}{{{t_{AB}}}}\\
\Rightarrow {v_c} + 5 = \frac{{AB}}{{5400}}\left( 1 \right)\\
{v_{nguoc}} = {v_c} - {v_n} = \frac{{AB}}{{{t_{BA}}}}\\
\Rightarrow {v_c} - 5 = \frac{{AB}}{10800}\left( 2 \right)\\
\frac{{\left( 1 \right)}}{{\left( 2 \right)}} \Rightarrow \frac{{{v_c} + 5}}{{{v_c} - 5}} = 2\\
\Rightarrow {v_c} = 15\left( {m/s} \right)\\
AB = \left( {{v_c} + {v_n}} \right){t_{AB}} = \left( {15 + 5} \right).5400 = 108000\left( m \right)
\end{array}\)
