A river is flowing from $W$ to $E$ with a speed of $5 \,m/min$. A man can swim in still water with a velocity $10\, m/min$. In which direction should the man swim so as to take the shortest possible path to go to the south.
A river is flowing from $W$ to $E$ with a speed of $5 \,m/min$. A man can swim in still water with a velocity $10\, m/min$. In which direction should the man swim so as to take the shortest possible path to go to the south.
$30^°$ with downstream
$60^°$ with downstream
$120^°$ with downstream
South
A river is flowing from $W$ to $E$ with a speed of $5 \,m/min$. A man can swim in still water with a velocity $10\, m/min$. In which direction should the man swim so as to take the shortest possible path to go to the south.
For shortest possible path man should swim with an angle $(90+\theta) $ with downstream.
From the fig, $\sin \theta = \frac{{{v_r}}}{{{v_m}}} = \frac{5}{{10}} = \frac{1}{2}$
$\therefore \theta= 30^°$
So angle with downstream $= 90^\circ + 30^\circ = 120^\circ $