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प्रश्न
A man standing 825 metres away from a cliff (steep rock) fires a gun. After how long will he hear its echo ? Speed of sound in air is 330 m/s.
उत्तर
We have to calculate time taken by the sound wave to reach the reflecting surface.
Given: Distance between the observer and reflecting surface d = 825 m
Velocity of sound ν = 330 m/s
We know the time taken by sound wave to reach the reflecting surface is,
t = 2d/ν
⇒ t = (2)(825)/330
⇒ t = 5 s
This is the required time.
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संबंधित प्रश्न
Which property of sound leads of the formation of echoes ?
In which medium, air or water, an echo is heard much sooner ? Why ?
The speed of sound in water is 1500 metres per second. How far away from an under-sea rock should a deep sea diver be so that he can hear his own echo ?
State the laws of reflection of sound.
Answer the following question in your own words.
Study the construction of the Golghumat at Vijapur and discuss the reasons for the multiple echoes produced there.
What is the minimum distance needed for an echo?
State two conditions necessary for hearing an echo.
Assertion: The sound which we hear again is called Echo.
Reason: The sensation of sound (Echo) persists in our brain for about 1 s.
What is an echo? Write the conditions to hear an echo.
Numerical problems:
An echo returned in 3s. What is the distance of the reflecting surface from the source given that the speed of sound is 330 ms-1?
