Question

What do you mean by vibratory motion?

Ans. The oscillatory motion in which the body assumes a new shape during its motion, is called vibratory

motion. In vibratory motion, a part of the body oscillates keeping its other part fixed.

2. What is sound?

Ans. Sound is a form of energy that produces the sensation of hearing in our years. Sound is produced

when a body vibrates. In other words, each source of sound is a vibrating body.

3. How is sound produced?

Ans. Sound is produced by the vibrations in a body. When the body stops vibrating, the sound produced

by it also ceases.

5. Name two sources of sound.

Ans. Each vibrating body is a source of sound. Two sources of sound are tuning fork and musical

instruments.

6. How do we produce sound?

Ans. We human beings produce sound when our vocal cords vibrate on blowing air through them by our

lungs.

7. The bees do not have voice-boxes but they still make sound. How?

Ans. Bees produce sound by moving their wings up and down very fast.

8. Can sound travel through a vacuum?

Ans. Sound cannot travel through a vacuum. Sound requires a medium for its propagation.

11. Can two persons hear each other on moon's surface? Give reason to support your answer.

Ans. Sound requires medium for transmission. It cannot travel through vacuum. Thus, two persons

cannot hear each other on moon's surface because on the moon and in space, there is no atmosphere.

12. What is a longitudinal wave?

Ans. In a longitudinal wave, the particles of air vibrate to and fro about their mean positions in the

direction of propagation of sound.

13. Define the following terms :

Amplitude, Time period, Frequency.

Ans.

Amplitude : The maximum displacement of a wave on either side of its mean position is known as the

amplitude. It is measured in metre.​

Answer 1

Answer:

New shape during it's motion