Question

a river is flowing at a speed of 3m/s. a man who can swim at 4m/s decides to cross the river in the shortest possible time . find the angle between the direction of his Motion as seen by an observer an the ground and direction of flow of river​

Answer 1

Answer:

Since he makes his strokes normal to the river current, the movement of the river will have no effect on the time of crossing the bank.

The time will be, T=

Speed

Distance

=

4

1

hr=0.25hr=15min.

In the same time, he will go down by

Distance=Speed x time=3km/hr x 0.25hr=0.75km=750m

Explanation:

I hope you give me brainlist..

Answer 2

Answer:

Explanation:

Correct option is

C

30  

∘

 west of north

Here, Velocity of swimmer in still water, v  

s

​

=10ms  

−1

 

Velocity of water flowing in river, v  

r

​

=5ms  

−1

 

From figure, sinθ=  

v  

s

​

 

v  

r

​

 

​

=  

10

5

​

=  

2

1

​

 

θ=sin  

−1

(  

2

1

​

)=30  

∘

 west of north