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9th Class Science Sound Question Bank Sound Summative Objective Problems

  • question_answer
    An echo is heard after 0.8 s, when a person fires a cracker 132.8 m from a high building. What is the speed of sound?

    A)  315 m/s                              

    B)  332 m/s

    C)  320 m/s                              

    D)  310 m/s

    Correct Answer: B

    Solution :

      \[t=0.8s\] \[d=132.8\text{ }m\] \[v=?\] We know, \[t=\frac{2d}{v}\] \[\Rightarrow \] \[0.8=\frac{2\times 132.8}{v}\] \[\Rightarrow \] \[v=\frac{2\times 132.8}{0.8}=332\,m/s\]


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