• # question_answer A person swims in a river aiming to reach exactly on the opposite point on the bank of a river. His speed of swimming is 0.5 m/s at an angle of $120{}^\circ$ with the direction of flow of water. The speed of water is A)  1.0 m/s                        B)  0.5 m/sC)  0.25 m/s             D)         0.43 m/s

Here v = 0.5 m/sec.     u=? $\sin \theta =\frac{u}{v}\Rightarrow \frac{u}{0.5}=\frac{1}{2}$or $u=0.25m{{s}^{-1}}$