Home
Class 12
MATHS
A bird is sitting on the top of a vertic...

A bird is sitting on the top of a vertical pole 20 m high and its elevation from a point O on the ground is `45^@`. It flies off horizontally straight away from the point O. After one second, the elevation of the bird from O is reduced to `30^@`. Then the speed ( in `m//s`) of the bird is

A

`20 sqrt2`

B

`20(sqrt3-1)`

C

`40 (sqrt2-1)`

D

`40 (sqrt3-sqrt2)`

Text Solution

Verified by Experts

The correct Answer is:
B
Promotional Banner

Topper's Solved these Questions

  • PROPERTIES OF TRIANGLES

    DIPTI PUBLICATION ( AP EAMET)|Exercise EXERCISE 2 (SPECIAL TYPE QUESTIONS) SET 1|10 Videos

  • PROPERTIES OF TRIANGLES

    DIPTI PUBLICATION ( AP EAMET)|Exercise EXERCISE 2 (SPECIAL TYPE QUESTIONS) Set -2|5 Videos

  • PROPERTIES OF TRIANGLES

    DIPTI PUBLICATION ( AP EAMET)|Exercise EXERCISE 1B|111 Videos

  • PRODUCTS OF VECTORS

    DIPTI PUBLICATION ( AP EAMET)|Exercise Exercise 2 (Special Type Questions) SET -D|14 Videos

  • QUADRATIC EXPRESSIONS

    DIPTI PUBLICATION ( AP EAMET)|Exercise EXERCISE 2 ( SPECIAL TYPE QUESTIONOS ) ( SET -4)|4 Videos

Similar Questions

Explore conceptually related problems

An aeroplane is moving one kilometer high from west to east horizontally . From a point on the ground due south the angle of elevation of the aeroplane is 60^(@) , and after 10 second, the angle of elevation of the aeroplane is observed as 30^(@) . Then the speed (in m/s)of the bird is

An aeroplane is moving one kilometer high from west to east horizontally. From a point on the ground due south, the angle of elevation of the aaeroplane is 60^(@) , and after 10 second, the angle of elevtion of the aeroplane is observed as 30^(@) , then the speed (in m//s ) of the aeroplane is

From the top of a 10 m height tree the angle of depression of a point on the ground is 30^@ then the distance of the point from the foot of the tree is

From the top of a 10 m high tower, the angle of depression of a point on the ground is found to be 30^@ . Find the distance of the point from the base of the tower is

The angle of depression from the top of a tower 100m height, at a point on the ground is 45^(@) ,. The distance of the point from the tower is…………….

The angle of depression from the top of a tower 12m height, at a point on the ground is 30^(@) . The distance of the point from the tower is…………….

Angle of elevation of the top of a building from a point on the ground is 30^(@) , Then the angle of depression of this point from the top of the building is…………..

A boy observed the top of an electrical pole to be at angle of elevation of 60^(@) when the observation point is 8m away from the foot of the pole then the height of the pole is……….m.

DIPTI PUBLICATION ( AP EAMET)-PROPERTIES OF TRIANGLES -EXERCISE 1C
  1. A tower subtends angles alpha,2 alpha, 3 alpha respectively at points ...

    Text Solution

    |

  2. The angle of elevation of a cloud from a point h mt above the surface ...

    Text Solution

    |

  3. The angle of elevation of a stationary cloud from a point 2500 mt abov...

    Text Solution

    |

  4. The angle of elevation of the top of the tower observed from each of t...

    Text Solution

    |

  5. A person stading on the bank of a river observerves that the angle of ...

    Text Solution

    |

  6. ABC is a triangular park with AB=AC=100 meters. A clock tower is situa...

    Text Solution

    |

  7. An aeroplane flying with uniform speed horizontally one kilometer abov...

    Text Solution

    |

  8. The upper 3//4^(th) portion of a vertical pole subtends an angle "Tan"...

    Text Solution

    |

  9. A vertical pole subtends an angle Tan^-1(1/2) at a point P on the grou...

    Text Solution

    |

  10. The angle of elevation of a stationar cloud from a point 2500 m above ...

    Text Solution

    |

  11. A lamp post is sittuated at the middle point M of the side AC of a tri...

    Text Solution

    |

  12. A tree stands vertically on the slant of the hills From a point A on t...

    Text Solution

    |

  13. An object is placed at a distance of 10 cm from a convex mirror of foc...

    Text Solution

    |

  14. Two ships leave a port at the same time . One goes 24km per hour in th...

    Text Solution

    |

  15. Two trees A and B are on the same side of a river. From a point C in t...

    Text Solution

    |

  16. The angle of elevation of the toop point P of the vertical tower PQ of...

    Text Solution

    |

  17. AB is a vertical pole with B at the ground level and and A at the top ...

    Text Solution

    |

  18. A person observes the top of a tower from a point A on the ground. the...

    Text Solution

    |

  19. A bird is sitting on the top of a vertical pole 20 m high and its elev...

    Text Solution

    |

  20. ABCD is a trapezium such that AB and CD are parallel and BC bot CD. If...

    Text Solution

    |