2. Sample Papers
  3. NTSE

NTSE Sample Paper NTSE SAT Practice Test-18

  • question_answer
    A stone is dropped into a well in which the level of water is h metre below the top of the h metre below the top of the well. If \[\upsilon \] is velocity of sound, the time T after which the splash is heard is given by

    A) \[T=2h/\upsilon \]                      

    B) \[T=\sqrt{\frac{2h}{g}}+\frac{h}{\upsilon }\]

    C) \[T=\sqrt{\frac{2h}{\upsilon }}+\frac{h}{g}\]     

    D) \[T=\sqrt{\frac{h}{2g}}+\frac{2h}{\upsilon }\]

    Correct Answer: B

    Solution :

    [b] The stone falls with acceleration g while sound comes back with constant velocity v. We have, \[h=\frac{1}{2}g{{t}_{1}}^{2}\,\,and\,\,h=v{{t}_{2}}\] So,   \[{{t}_{1}}+{{t}_{2}}=\sqrt{\frac{2h}{g}}+\frac{h}{v}\] \[\therefore \,\,\,\,\,\,\,\,\,\,\,\,\,\,T=\sqrt{\frac{2h}{g}}+\frac{h}{v}\]


You need to login to perform this action.
You will be redirected in 3 sec spinner