Home
Class 12
PHYSICS
A ball is dropped from a height of 20 m ...

A ball is dropped from a height of 20 m above the surface of water in a lake. The refractive index of water is 4.3. A fish inside the lake, in the line of fall of the ball, is looking at the ball. At an instant, when the ball is 12.8 m above the water surface, the fish sees the speed of the ball as `[Take _(g)=10m/s^(2).]`

A

9 m/s

B

12 m/s

C

16 m/s

D

21.33 m/s

Text Solution

Verified by Experts

The correct Answer is:
C
Promotional Banner

Topper's Solved these Questions

  • GEOMETRICAL OPTICS

    MOTION|Exercise Exercise - 4 | Level-I|25 Videos

  • FLUID

    MOTION|Exercise Exercise-4 level-II|5 Videos

  • GRAVITATION

    MOTION|Exercise Exercise - 4 Section - B Previous Years Problems|15 Videos

Similar Questions

Explore conceptually related problems

A ball is dropped from a height of 20m above the surface of water in a lake. The refractive index of water is 4//3 . A fish inside the lake, in the line of fall of the ball, is looking at the ball. At an instant, when the ball is 12.8m above the water surface, the fish sees the speed of ball as (g=10m//sec^2)

A ball is dropped from a height of 100 m. At the surface of the earth, 20% of its energy is lost. To what height the ball will rise?

A ball is dropped from height 10 m . Ball is embedded in sand 1 m and stops, then

A rubber ball dropped from a height of 20m (g=10m/s^(2)) falls on the roof of an elevator going up at 2m/s. If the collision of the ball with the elevator is elastic, the ball rebounds with a velocity of?

A rubber ball dropped from a height of 20m (g=10m/s^(2)) falls on the roof of an elevator going up at 2m/s .If the collision of the ball with the elevator is elastic, the ball rebounds with a velocity of

MOTION-GEOMETRICAL OPTICS-Exercise - 4 | Level-II
  1. A light beam is traveling from Region I to region IV (refer figure). T...

    Text Solution

    |

  2. An optical component and an object S placed along its optic axis are g...

    Text Solution

    |

  3. A ball is dropped from a height of 20 m above the surface of water in ...

    Text Solution

    |

  4. A student performed the experiment of determination of focal length of...

    Text Solution

    |

  5. A ray OP of monochromatic light is incident on the face AB of prism AB...

    Text Solution

    |

  6. The focal length of a thin biconvex lens is 20 cm. When an object is m...

    Text Solution

    |

  7. A biconvex lens of focal length 15 cm is in front of a plane mirror. T...

    Text Solution

    |

  8. A large glass slabe (mu=5//3) of thickness 8cm is placed over a point ...

    Text Solution

    |

  9. Image of an object approaching a convex mirror of radius of curvature ...

    Text Solution

    |

  10. Two transparent media of refractive indices mu(1) and mu(3) have a sol...

    Text Solution

    |

  11. An initially parallel cylindrical beam travels in a medium of refracti...

    Text Solution

    |

  12. An initially parallel cylindrical beam travels in a medium of refracti...

    Text Solution

    |

  13. The speed of light in the medium is

    Text Solution

    |

  14. A light ray travelling in glass medium is incident of glass- air inter...

    Text Solution

    |

  15. Water (with refractive index = 4/3) in a tank is 18 cm deep. Oil of re...

    Text Solution

    |

  16. A bi-convex lens is formed with two thin plano-convex lenses as shown ...

    Text Solution

    |

  17. Most materials have the refractive index, n gt 1. So, when a light ray...

    Text Solution

    |

  18. Most materials have the refractive index, n gt 1. So, when a light ray...

    Text Solution

    |

  19. The image of an object, forme by a plano-convex lens at a distance of ...

    Text Solution

    |

  20. A ray of light travelling in the direction (1)/(2)(hat(i)+sqrt(3)hat(j...

    Text Solution

    |