A) \[30{}^\circ \]east of south
B) \[60{}^\circ \]east of south
C) \[60{}^\circ \]west of south
D) \[30{}^\circ \]west of north
Correct Answer: A
Solution :
Let the swimmer swims at an angle\[\theta \]with the vertical from figure. \[\sin \theta =\frac{{{v}_{r}}}{{{v}_{b}}}\] where\[{{v}_{r}}\]is velocity of river,\[{{v}_{b}}\]is velocity of man. Given, \[{{v}_{r}}=5m/\min ,{{v}_{b}}=10m/\min \] \[\therefore \] \[\sin \theta =\frac{5}{10}=\frac{1}{2}\] \[\Rightarrow \] \[\theta ={{30}^{o}}\] The component\[10\text{ }sin\theta ,\]of swimmers velocity will cancel the velocity of river and the swimmer takes the shortest distance to the south. Therefore, direction is\[30{}^\circ \]east of south.You need to login to perform this action.
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