Get Answers to all your Questions

header-bg qa

A river flows from west to east at a speed of  5\ \frac{m}{min}. There is a man on the south bank of the river who can swim to a speed of  10\ \frac{m}{min} in calm water and wants to swim across the river in the minimum time. He must swim in one direction:

Option: 1

Due north


Option: 2

30^{\circ} east to north


Option: 3

30^{\circ} west to north.


Option: 4

60^{\circ} east to north


Answers (1)

Let the time is taken to cross the river be t.

t=\frac{d}{V_s}cos\theta

For the time t to be minimum cos\vartheta should be maximum,

 \theta should be   0

Therefore, swimmer should swim due north.

 

Posted by

Sumit Saini

View full answer

NEET 2024 Most scoring concepts

    Just Study 32% of the NEET syllabus and Score up to 100% marks