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/s

C)  0.25 m/s             

D)         0.43 m/s

Correct Answer: C

Solution :

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