River Boat Problem |Condition When The Boatman Crosses The River In Shortest Interval Of Time |Condition When The Boatman Wants To Reach Point B, At A Point Just Opposite From Where He Started |Exercise Questions

Questions|River Boat Problem |Shortest Time |To Reach Opposite to the Starting Point

Given |V_br| = 4 m//s = magnitude of velocity of boatman with respect to river, v_r= 2 m//s in the directior shown. Boatman wants to reach from point A to point B. At what angle theta should he row his boat ?

Width of a river is 30 m, velocity is 4 m//s and rowing velocity is 5 m//s (a) Make the velocity diagram for crossing the river in shortest time. Then, find this shortest time, net velocity of boatman and drigt along the river. (b) Can the boatman reach a point just oppsite on the other shore? If yes then make the velocity diagram, the direction in which the should row his boat and the time taken to cross the river in this case. (c) How long will it iake hom to row 10 m up the stream and then back to his starting point?

A boat man can rown with a speed of 10 km h^(-1) in still water. If the river flows steadily at 5 km //h , in which direction showld the boatman row in order to reach a point on the other bank directly opposite to the point from wher he stared ? The width of the river is 2km .

Velocity of a boat relative to river current and river current velocity are equal in magnitude. Starting from point A on the southern bank, the boatman wants to reach a point B on the nothern bank in north - east from A . In which direction he has to steer the boat?

Two persons P and Q crosses the river starting the point A on one side to exactly opposite point B on the other bank of the river. The person P crosses the river in the shortest path. The person Q crosses the river in shortest time and walks back to point B .Velocity of river is 3 kmph and speed of each person is 5kmph w.r.t river. If the two persons reach the point B in the same time, then the speed of walk of Q is .

A man with some passengers in his boat, starts perpendicular to flow of river 200 m wide and flowing with 2 m//s. Speed of boat in still water is 4 m//s. When he reaches half the width of river the passengers asked him that they want to reach the just opposite end from where they have started. (a) Find the direction due which he must row to reach the required end. (b) How many times more time, it would take to that if he would have denied the passengers?

A river of width omega is flowing with a uniform velocity v. A boat starts moving from point P also With velocity v relative to the river. The direction of resultant velocity is always perpendicular to the line joining boat and the fixed point R. Point Q is on the opposite side of the river. P, Q and R are in a straight line. If PQ=QR=omega, find (a) the trajectory of the boat, (b) the drifting of the boat and (c) the time taken by the boat to cross the river.

The river 500 m wide is flowing with a current of 4kph. A boat starts from one bank of the river wishes to cross the river at right angle to stream direction. Boatman can row the boat at 8 kph. In which direction he should row the boat. What time he ''ll take to cross the river ?

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?