Activity 13.9 Class 8 Science Chapter 13 Solution

Activity 13.9 Class 8 Science Chapter Sound

In this post, you will find NCERT Science Class 8 Chapter 13 activity 13.9 and after reading this, you can understand the meaning of sound, characteristics of sound, propagation of sound, properties of sound and types of sound waves. You should also go through activity 13.7 of chapter 13.

Activity

   ·     Take a metre scale or a long metal rod and hold its one end to your ear.

   ·      Ask your friend to gently scratch or tap at the other end of the scale.

   ·      Can you hear the sound of the scratching?

   ·      Ask your friends around you if they were able to hear the same sound?

      

 Activity 13.9 Class 8 Science Chapter 13 Solution

Observation and explanation

The person holding the rod near his ear can hear the scratching sound but the others can’t hear the sound.

The sound can travel through solid materials like wood or metal also.

We can use this property of sound in making a toy telephone as shown in the figure.

We have already learnt that sound can travel through liquids in activity 13.8.

Conclusion

We have learnt so far that vibrating objects produce sound and it is carried in all directions in a medium. The medium could be a gas, a liquid or a solid.

 Related Topics

1. Activity 13.10

2. Activity 13.8