Question

A boat moves relative to water with a velocity
which is n times less than the river flow
velocity .At what angle to the stream
must the boat move to minimize
direction
drifting? (u is velocity of water, v is velocity
of boat)​

Answer 1

Answer:

velocity of boat :

               

         

         

         

3) Let the width of river be 'd' . 

Time required to cross the river,t :  

Since, we observed that ,so drift can't be 0.

4) That is, 

     Drift ,x =    

                 = 

For Drift to be minimum, 

 

5) Hence, angle made with the vertical is 30 degree.

Therfore,angle made with the direction of river flow is 90+30=120 degree.

  

Hence , value of n is 3. 

e