Two swimmers ‘A’ & ‘B’, one located on one side and other on the another side of a river are situated at a distance ‘D’ from each other. Line joining them is making an angle θ with the direction perpendicular to flow. The speed of each swimmer with respect to still water is ‘u’ & speed of river flow is v r . Both A & B start swimming at the same time in the direction parallel to line AB towards each other and they keep on swimming in same direction. Then,
Text Solution
Verified by ExpertsCHECK THE SOLUTION
v r = u
Sol. 
Velocity of approach along line joing them
= u – V r sin θ + u + V r sin θ = 2u
So time t = 
Ans.
For path to be at right angle to each other, their velocity vector with respect to ground must be right angle. Taking axis system as shown
= (u sin θ + v r ) 
= (v r – u sin θ ) 
For 
& 
to perpendicular 
. 
= 0
(u sin θ + v r ) (v r – usin θ ) – u 2 cos 2 θ = 0
⇒ v r = u
Prepare Smarter with CGP Edu
Get practice questions, solutions, and test series in one place.
Write a Review
Share your experience with this question and solution.
Commentary
Send your comment, doubt, correction, or feedback to admin.
Similar Questions
Explore conceptually related problems