Crossing of River

Crossing River In Minimum Time

A swimmer can swim in still water with a speed of 3 ms^(-1) While crossing a river his average speed is 5 ms^(-1) If crosses the river in the shortest possible time, what is the speed of flow of water ?

Two ports, A and B, on a north-south line ar separated by a river of width D. The river flows east with speed u. A boat crosses the river starting from port A. The speed of the boat relative to the river is v. Assume v=2u Q. The boat crosses the river from A to the other side in shortest possible time, then how far is the boat from the port B after crossing the river

47.A man can row a boat with 4kmph in still water.If he is crossing a river where the current is 8kmph .The time take to cross the river in shortest path is (k)/(sqrt(3))hr .Where k ' is (width of the river is 8km )

A man can row a boat with 8 kmph in still water.If he is crossing a river of width 8km where the current is 4kmph , then the time taken to cross the river in shortest time is (k/sqrt(3)) hr.The value of 'k' is?

A boatman finds that he can save 6 s in crossing a river by the quickest path than by the shortest path. If the velocity of the boat and the river be, respectively, 17 ms^-1 and 8 ms^-1 , find the river width.

You are going to your village. You know swimming and while crossing a river you hear the crying of a drowning child. You would

A man can row a boat with 4km/h in still water, if he is crossing a river where the current is 2 km/h. (a) In what direction will his boat be holded, if he wants to reach a point on the other bank, directly opposite to starting point? (b) If width of the river 4km, how long will the man take to cross the river, with the condition in part (a)? (c) In what direction shou ld he heat the boat if he wants to cross the river in shorest time and what is this minimum time? (d) How long will it take him to row 2 km up the stream and then back to his starting point?