A river is flowing from west to east with a speed $5 \mathrm{~m} \mathrm{~s}^{-1}$. A swimmer can sw

Question

A river is flowing from west to east with a speed $5 \mathrm{~m} \mathrm{~s}^{-1}$. A swimmer can swim in still water at a speed of $10 \mathrm{~m} \mathrm{~s}^{-1}$. If he wants to start from point $A$ on south bank and reach opposite point $B$ on north bank, in what direction should he swim?

Professor PC Thomas Classes · Answer

(c) : Here, Velocity of swimmer in still water, $v_s=10 \mathrm{~m} \mathrm{~s}^{-1}$ Velocity of water flowing in river, $v_r=5 \mathrm{~m} \mathrm{~s}^{-1}$ From figure, $\sin 	heta=\frac{v_r}{v_s}=\frac{5}{10}=\frac{1}{2}$ \ $ 	heta=\sin ^{-1}\left(\frac{1}{2}ight)=30^{\circ} 	ext { west of north } $