Unit - 6 Sound

 Unit - 6

Sound

summary

1. Sound originates from the constant vibration of objects.

2. Sharpness of sound is called sharpness.

3. A child's voice is louder than an adult's.

4. Bigger sounds have higher pitch.

5. The pitch of small sounds is low.

6. A sound with a higher pitch is transmitted to a greater distance.

7. Sound transmission is transmitted as waves.

8. Sound transmission requires a medium.

9. Sound cannot be transmitted without a medium (in zero space).

1. Fill in the blank

(a) Sound originates from different objects that are vibrating.

(b) Murli Bazau sound is generated.

(c) Sound originating from metal is metallic.

(d) A sound with more power has more loudness.

(e) Sound is transmitted as longitudinal waves.

(f) Sound transmission requires a medium.

(g) The velocity of sound in air is 340 meters per second.

Write answers to the following questions:

  (a) When the ringing bell is touched with the hand, the sound stops, why?

  (b) Write any four sources of sound.

  (c) What is the difference between male and female sounds?

  (d) What should I do to increase the sharpness of the sound coming out of the guitar? rk nu dai iura ta s se jhav u

  (e) How does a high pitched sound come out? Why is such a sound transmitted far?

  (f) Draw a picture of a wave originating in water.

  (g) Why does the sound coming from a source get fainter when it reaches a distance? explanation

Answer 👉 

(a) When a ringing bell is touched with the hand, the sound stops because the hand stops the vibrations of the bell. Sound is created when an object vibrates and causes the air around it to vibrate. When the hand touches the bell, it stops the vibrations of the bell, and therefore stops the sound.

(b) Four sources of sound are:

• Human voice
• Musical instruments
• Animals
• Machines

(c) The difference between male and female sounds is the pitch. Male voices tend to be lower in pitch than female voices. This is because the vocal cords of men are longer and thicker than the vocal cords of women. The longer and thicker the vocal cords, the lower the pitch of the sound.

(d) To increase the sharpness of the sound coming out of a guitar, you can:

• Use a thinner pick
• Play with your fingers instead of a pick
• Strum the strings more quickly
• Fret the strings closer to the neck of the guitar

(e) A high-pitched sound is created when an object vibrates at a high frequency. The higher the frequency of the vibration, the higher the pitch of the sound. High-pitched sounds are transmitted far because they have a shorter wavelength than low-pitched sounds. A shorter wavelength means that the sound waves can travel more easily around obstacles.

(f) Here is a picture of a wave originating in water:

do your self

(g) The sound coming from a source gets fainter when it reaches a distance because the sound waves spread out as they travel. The further the sound waves travel, the more they spread out, and the less energy they have. This is why the sound of a car horn becomes fainter as the car drives away.