V K Sally and R Goel Solutions for Chapter: Sound, Exercise 9: Practice Problems

A boy counts the number of ripples reaching the shore for $12$ seconds. He finds that $72$ ripples reach the shore. What is the frequency of the waves?    

A plastic ruler is held near the rotating wheel of a cycle such that it produces sound every time the spoke of the wheel strikes it. If $20$ clicks are heard in $0.4 \mathrm{s}$, calculate the frequency of the sound produced.    

A person fires a gun in front of a building $167 \mathrm{m}$ away. If the speed of sound is $334 \mathrm{m} {\mathrm{s}}^{-1}$, calculate the time in which he hears an echo.

An echo is heard after $0.8 \mathrm{s}$, when a person fires a cracker, $132.8 \mathrm{m}$ from a high building. Calculate the speed of sound.

The speed of sound is $310 \mathrm{m} {\mathrm{s}}^{-1}$. A person fires a gun. An echo is heard after $1.5 \mathrm{s}$. Calculate the distance of person from a cliff from which echo takes place.