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If you hear the thunder 20 seconds after...

If you hear the thunder 20 seconds after you see the flash of lightning, how far from you hasthe lightning occurred? (Speed of sound in air = `340 m/s`)

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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 )

afires a gun. He heard the echo of the sounds from the first building after 2 seconds and echo i from the second building after 3 seconds. Find the distance between two buildings. (Speed of sound in air = 340 m/s )

Solve the following example: A person standing between two hills fired a gun and heard the first echo after 0.5 s and the second echo after 0.9 s. Find the distance between two hills. (speed of sound in air =340 m//s )

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Answer the following question orally: Have you seen a flash of lightning in the sky? When?

A man shouts loudly close to a high wall. He hears an echo. If the man is at 40 m from the wall, how long after the shout will the echo be heard? (speed of sound in air = 330 m//s )

A tuning fork of frequency 340 Hz is vibrated just above the tube of 120 cm height. Water is poured slowly in the tube. What is the minimum height of water necessary for the resonance? (speed of sound in the air = 340m/s)

A man sets his watch by a whistle that is 2 km away. How much will his watch be in error (speed of sound in air 330 m//s ) ?

A soldier standing between two hills hears two echoes after firing the gun. The first echo is heard after 1.2s and the second echo after 2.4s. Find the separation between the two hills.(speed of sound in air = 340m//s )

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CHETANA PUBLICATION-Study of Sound-EXERCISE
  1. If you hear the thunder 20 seconds after you see the flash of lightnin...

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  2. The unit of frequency is …………… .

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  3. The normal hearing range for humans is ………… .

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  4. Sound will not travel through ……….. .

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  5. SI unit of …………..is Hertz (Hz).

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  6. The velocity of sound is inversely proportional to the………… .

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  7. Sound waves with frequency greater than 20 kHz are called……….. .

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  8. The loudness of a sound depends upon ………… .

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  9. …../… are used in sonography.

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  10. The ……….receives the vibrations coming from the membrane and converts ...

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  11. Sound will not travel through ……….. .

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  12. SI unit of …………..is Hertz (Hz).

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  13. The loudness of a sound depends upon ………… .

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  14. …………are used in sonography.

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  15. Match the columns:

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  16. The intensity of reverberation is higher in a closed and empty house.

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  17. Bats can navigate in dark.

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  18. Sound travels faster in iron than in air.

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  19. The roof of a movie theatre and a conference hall is curved. Why?

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  20. The intensity of reverberation is higher in a closed and empty house.

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  21. What is an echo? What factors are important to get a distinct echo?

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