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9th Class Science Sound Question Bank Sound Summative Objective Problems

  • question_answer
    A man stands in between two cliffs and explodes a cracker. He hears the first echo after 0.6s and the second echo after 2.4s. Calculate the distance between the cliffs, (speed of sound = 336 m/s)

    A)  515 m                                  

    B)  520 m

    C)  504 m                  

    D)  505 m

    Correct Answer: C

    Solution :

      Distance of person from nearer cliff, \[{{d}_{1}}=\frac{v\times t}{2}\]\[\Rightarrow \]\[{{d}_{1}}=\frac{336\times 0.6}{2}=100.8\,m\] distance of person from farther cliff, \[{{d}_{2}}=\frac{v\times t}{2}\] \[\Rightarrow \]\[{{d}_{2}}=\frac{336\times 2.4}{2}=403.2m\] The distance between the cliffs\[={{d}_{1}}+{{d}_{2}}\] \[=100.8m+403.2\text{ }m=504\text{ }m\]          


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