A swimmer wishes to cross a river of width $d$ flowing with a velocity $u$. The swimmer can swim with a velocity $v$ relative to still water. If the swimmer swims at an angle $heta$ with the upstream direction such that he drifts a minimum distance downstream, then $an heta$ is given by:

A swimmer can swim at a speed of 4 km/h in still water. He wants to cross a river flowing at 2 km/h. In what direction should he swim to cross the river in the shortest time?

Following forces start acting on a particle at rest at the origin of the co-ordinate system simultaneously ${{\rm{\vec F}}_1} = 5\hat i - 5\hat j + 5\hat k,{\rm{\;\;\;}}{{\rm{F}}_2} = 2\hat i + 8\hat j + 6\hat k,{{\rm{F}}_3} = - 6\hat i + 4\hat j - 7\hat k,{{\rm{F}}_4} = - \hat i - 3\hat j - 2\hat k.$ The particle will move

A boat capable of a speed $v$ in still water wants to cross a river of width $d$ flowing with speed $u$. If the boat crosses the river in minimum time, the drift along the river is:

A boat can travel with a speed of 10 km/h in still water. If the speed of the river is 2 km/h, what is the speed of the boat downstream?

A boat of mass 50 kg is ${O^ + }$ the rest. A dog of mass 5 kg moves in the boat with a velocity of 20 m/s. What is the velocity of a boat? (nearly)

A motorboat whose speed in still water is 15 km/h must aim upstream at an angle $heta$ with respect to the shore to travel directly across a river flowing at 5 km/h. What is $\sinheta$?

If a boat travels with the river current, its speed is called:

A man rows a boat downstream for a distance of 6 km in 1 hour. He then rows upstream for the same distance and finds that it takes him 2 hours. The speed of the stream is:

The speed of a swimmer in still water is 20 m/s. The speed of river water is 10 m/s and is flowing due east. If he is standing on the south bank and wishes to cross the river along the shortest path the angle at which he should make his strokes w.r.t. north is given by:

A swimmer can swim at 5 km/h in still water. He wants to cross a river flowing at 3 km/h. In what direction should he swim to cross the river in the shortest time?