Question

A boat is to cross a river of width 500 m. The velocity of the river flow is 5 kmph and the velocity of the boat is 10 krnph. The angle at which the boat is to be rowed with the direction of river flow velocity so that the boat can cross the river along shortest path is

• A. ${120}^o$
• B. ${135}^o$
• C. ${150}^o$
• D. ${60}^o$

Answer 1

The correct option is A ${120}^o$

$\begin{array}{c}\sin \theta =\frac{5}{10}=\frac{1}{2}\\ \therefore \theta ={30}^{\circ }\\ \therefore anglewithriverflow={120}^{\circ }\end{array}$.

hence, the options $A$ is the correct answer.