Home
Class 11
PHYSICS
A river is flowing from east to west at ...

A river is flowing from east to west at a speed of `5(m)/(min)`. A man on south bank of river, capable of swimming `(10m)/(min)` ini still water, wants to swim across the river in shortest time. He should swim

A

Due north

B

Due north-east

C

Due north-east with double the speed of river

D

None of these

Text Solution

Verified by Experts

The correct Answer is:
A


`y:v cos thetat=d`
`t=d/(v cos theta)`
`t` will be minimum, if `cos theta` is maximum
`(cos theta)_(max)=1 implies theta=0`
To cross the river in minimum time, the man should swim perpendicular to the river flwo, i.e. due north
Promotional Banner

Topper's Solved these Questions

  • RELATIVE MOTION

    CP SINGH|Exercise EXERCISE|33 Videos

  • NEWTONS LAWS OF MOTION

    CP SINGH|Exercise EXERCISES|84 Videos

  • ROTATIONAL MOTION

    CP SINGH|Exercise Exercise|172 Videos

Similar Questions

Explore conceptually related problems

Statement-1: A river is flowing from east to west at a speed of 5m/min. A man on south bank of river, capable of swimming 10 m/min in still water, wants to swim across the river in shortest time. He should swim due north. Statement-2 : For the shortest time the man needs to swim perpendicular to the bank.

A river is flowing from east to west at a speed of 5m//min . A man on south bank of river, capable of swimming 10m//min in still water, wants to swim across the river in shortest time. He should swim

A river flowing from east to west at a speed of 5 m//"min" . A man on south bank river, capable of swimming 10 m//"min" in still water, wants to swim across the river in shorter time, he should swim:-

A river is flowing from west to east at a speed of 5m//s . A man on the south bank of the river capable of swimming at 10m//s in a still water wants to swim, across the river in a shortest time. He should swim in a direction

A river is flowing from west to east at a speed of 5m/ minute. A man on the south bank of the river, capable of swinning at 10m/minutes in still water, wants to swin across the river in the shortest time . He should siwn in a direction :

A river is flowing from north to south at a speed of 0.3 kph. A man on the west bank of the river, capable of swimming 1 kph in still water, wants to swim across the river in the shortest time. He should in a direction:

A river is following from west to east at a speed of 5m/minute. A boy on the south bank of the river, capable of swimming at 10 meters/minute in still water, wants to swin across the river in the shortest time, (i) Find the direaction in which he should swin, (ii) find the direction when drift along the river is zero.

A river is flowing from west to east at a speed of 5 metres per minute.A man on the south bank of the river, capable of swimming at 10 metres per minute in still water, wants to swim across the river in the shortest time. He should swim in a direction.

A river is flowing from west to east at a speed of 5 metres per minute . A man on the south bank of the river , capable of swimming at 10 metres per minute , in still water , wants to swim across the river in the shortest time . He should swim in a direction

CP SINGH-RELATIVE MOTION-EXERCISE
  1. Four particles A, B, C and D are situated at the cornerst of a square ...

    Text Solution

    |

  2. Six particles situated at the corners of a regular hexagon of side a m...

    Text Solution

    |

  3. A particle A is at origin and particle B is at distance y=-d at t=0. T...

    Text Solution

    |

  4. A police jeep is chasing with, velocity of 45 km//h a thief in another...

    Text Solution

    |

  5. A cart is moving horizontally along a straight line with constant spee...

    Text Solution

    |

  6. A boat is moving with a velocity 3 hat i+ 4hat j with respect to groun...

    Text Solution

    |

  7. A boat crosses a river with a velocity of 8(km)/(h). If the resulting ...

    Text Solution

    |

  8. A man takes 3 h to cover a certain distance along the flow and takes ...

    Text Solution

    |

  9. A river 500m wide is flowing at a rate of 4 m//s. A boat is sailing at...

    Text Solution

    |

  10. In the previous problem, the distance travelled by boat along the flow...

    Text Solution

    |

  11. A boat having a speed of 5km//hr. in still water, crosses a river of w...

    Text Solution

    |

  12. A man crosses a 320m wide river perpendicular to the current in 4 min....

    Text Solution

    |

  13. A man can swim in still water ast a speed of 3 km/h. He wants to cross...

    Text Solution

    |

  14. A man can swim in still water ast a speed of 3 km/h. He wants to cross...

    Text Solution

    |

  15. A man can swim at a speed of 3 km h^-1 in still water. He wants to cro...

    Text Solution

    |

  16. In the previous problem, How far from the point directly opposite to t...

    Text Solution

    |

  17. A person aiming to reach the exactly opposite point on the bank of a s...

    Text Solution

    |

  18. A river is flowing from west to east with a speed of 5 m//min. A man c...

    Text Solution

    |

  19. A river is flowing from east to west at a speed of 5(m)/(min). A man o...

    Text Solution

    |

  20. A man can swim with velocity v relative to water. He has to cross a ri...

    Text Solution

    |