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प्रश्न
The drawing shows a ship 800 m from a cliff. A gun is fixed on the ship. After 5 seconds the people at the front of the ship hear the sound of the gun again.
(a) What is the name of this effect ?
(b) What happens to the sound at the cliff ?
(c) How far does the sound travel in 5 seconds ?
(d) Calculate the speed of sound.
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उत्तर
(a)The name of this effect is echo.
(b) Sound gets reflected back after reflecting from the cliff.
(c) Distance covered by sound wave in 5 s can be calculated as follows:
Incident sound travels distance (dI) = 800 m
Sound after reflection travels (dR) = 800 m
Total distance travelled by sound
= dI + dR
= (800 + 800) m
= 1600 m
(d) We have to calculate the speed of sound.
Given: Distance of cliff d = 800 m
Time taken to listen to the echo t = 5 s
So , time taken to reach the cliff `(t_1) = 5/2` s
So , speed of sound is
= `d/t_1`
= `(800 xx 2)/5` m/s
= 320 m/s
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संबंधित प्रश्न
In which of the three media, air, water or iron, does sound travel the fastest at a particular temperature?
Write the approximate speed of sound in water .
Which of the following is the speed of sound in copper and which in aluminium?
(a) 5100 m/s
(b) 1500 m/s
(c) 3750 m/s
The maximum speed of vibrations which produce audible sound will be in :
Nita heard the sound of lightning after 4 seconds of seeing it. What was the distance of the lightning from her?
(The velocity of sound in air is 340 m/s.)
Why does the flash of lighting reach earlier than the sound of thunder?
The velocity of sound in air at a particular temperature is 330 ms–1. What will be its value when temperature is doubled and the pressure is halved?
When temperature increases the speed of sound ______.
On which factors does the speed of sound in the gaseous medium depend?
Numerical problems:
Two persons are at opposite ends of a steel rod. One strikes the end of the rod with a stone. Find the ratio of time taken by the sound wave in the air and in steel to reach the second person. (Sound of speed in steel = 5960 ms-1, Sound of speed in air = 344 ms-1).
