Question

A man capable of swimming with a velocity u in still water ,wants to cross a river of width d flowing with a velocity v.find the angle in which he should be directed to reach at the exactly opposite point.what is the value of the shortest time?

Answer 1

Answer:

     sinα =$\frac{v}{\sqrt{v^{2}+u^{2}  } }$

      T = $\frac{d}{\sqrt{v^{2}+u^{2}  } }$

Explanation: α is the angle angle in which he should be directed to reach at the exactly opposite point. T is the value of shortest time.

For explanation see the attached image.