Home
Class 11
PHYSICS
A man is crossing a river flowing with v...

A man is crossing a river flowing with velocity of `5m//s`. He reaches a point directly across at a distance of 60m in 5 sec. His velocity in still water should be

A

`12m//s`

B

`13m//s`

C

`5m//s`

D

`10m//s`

Text Solution

Verified by Experts

The correct Answer is:
B
The resultant velocity should be in the direction of resultant displacement

So time`=60/sqrt(v_(m)^(2)-5^(2))=5 :' v_(rm)=13 m//s`
Promotional Banner

Topper's Solved these Questions

  • KINEMATICS

    ALLEN|Exercise EXERCISE-02|57 Videos

  • KINEMATICS

    ALLEN|Exercise EXERCISE-03|6 Videos

  • KINEMATICS

    ALLEN|Exercise Integer Type Question|3 Videos

  • ERROR AND MEASUREMENT

    ALLEN|Exercise Part-2(Exercise-2)(B)|22 Videos

  • KINEMATICS (MOTION ALONG A STRAIGHT LINE AND MOTION IN A PLANE)

    ALLEN|Exercise BEGINNER S BOX-7|8 Videos

Similar Questions

Explore conceptually related problems

A man is crossing a river flowing with velocity of 5m//s . He reaches a point directly across at a distance of 60m in 5sec. his velocity in still water should be

A river of width 80m is flowing at 6 m/s. A motorboat crosses the river in 10s and reaches a point directly across on the other river bank. The velocity of motorboat in still water is :

A ,man wishing to cross a river flowing with velocity u jumps at an angle theta with the river flow. (a) Find the net velocity of the man with respect to ground if he can swim with speed v in still water. (b) In what direction does the boat actually move ? ( c) Find how far from the point directly opposite to the starting point does the boat reach the opposite bank, if the width of the river is d .

A man wishes to cross a river of width 120 m by a motorboat. His rowing speed in still water is 3 m//s and his maximum walking speed is 1m//s . The river flows with velocity of 4 m//s . (a) Find the path which he should take to get to the point directly opposite to his starting point in the shortest time. (b) Also, find the time which he takes to reach his destination.

A man wishes to swim across a river 40 m wide flowing with a speed of 3m/s. such that he reaches the point just infront on the other bank in time not greater than 100s. The angle made by the direction he swims and river flow direction is :-

Velocity of boat in still water is 13 m/s. If water flows ina river with a velocity of 5 m/s. What is the difference in times taken by him to cross the river in the shortest path and in the shortest time. If the width of the river is 10 m.

A motor boat is to reach to a point 30^(@) upstream on other side of a river flowing with velocity 5 m//s .Velocity of motor boat with respect to water is 5sqrt3m//sec .The driver should steer the boat at an angle of

A man can swim in still water ast a speed of 3 km/h. He wants to cross a river that flows at 2 km/h and reach the point directly oposite to his starting point. A. In which diretionshoeld he try to swim (that is, find the angle his body makes wilth the river flow)? b. How much time will he take to cross the river if the river is 500 m wide?

A river flows at 3 m/s and is 300 m wide . A man swing across the rivers with a velocity of 2 m/s directed always perpendicular to the flow of current . (a) How long does it take the man to cross the river ? (b) In what direction does he actually moves to cross the relative to the shore ? (c) How far down the fiver(from the starting point ) does he reach the opposite bank?

ALLEN-KINEMATICS-EXERCISE-01
  1. A boat has a velocity 4m//s towards east with respect to river is flow...

    Text Solution

    |

  2. Raindrops are falling vertically with a velocity 10 m//s. To a cyclist...

    Text Solution

    |

  3. A man is crossing a river flowing with velocity of 5m//s. He reaches a...

    Text Solution

    |

  4. A boat which has a speed of 5 km per hour in still water crosses a riv...

    Text Solution

    |

  5. A river flowing from east to west at a speed of 5 m//"min". A man on s...

    Text Solution

    |

  6. Two particles P and Q are moving with velocity of (hat(i)+hat(j)) and ...

    Text Solution

    |

  7. From a motorboat moving downstream with a velocity 2 m//s with respect...

    Text Solution

    |

  8. A small ball is projected up a smooth inclined plane with an initial s...

    Text Solution

    |

  9. Graph I and II give coordinates x(t) and y(t) of a particle moving in ...

    Text Solution

    |

  10. Particle is dropped form the height of 20m from horizontal ground. The...

    Text Solution

    |

  11. The total speed of a projectile at its greater height is sqrt(6/7) of ...

    Text Solution

    |

  12. A projectill is projected at an angle (alpha gt 45^(@)) with an initia...

    Text Solution

    |

  13. A particle is projected form a horizontal plane (x-z plane) such that ...

    Text Solution

    |

  14. A particle is dropped from a height h. Another particle which is initi...

    Text Solution

    |

  15. A particle is projected from a tower as shown in figure, then find the...

    Text Solution

    |

  16. In the arrangement shown in figure the ends P and Q of an inextensible...

    Text Solution

    |

  17. A block is dragged on a smooth plane with the help of a rope which mov...

    Text Solution

    |

  18. A weightless inextensible rope rests on a stationary wedge forming an ...

    Text Solution

    |

  19. If acceleration of M is a then acceleration of m is

    Text Solution

    |

  20. If acceleration of A is 2m//s^(2) to left and acceleration of B is 1m/...

    Text Solution

    |