Activity 8.7 Class 9 Science Chapter 8 Motion Solution

 Activity 8.7 Class 9 Science Chapter 8 Motion Solution

Activity 8.7Class 9 Science belongs to Chapter 8 Motion Class 9 Science. You will get a complete solution with an explanation and a conclusion. After reading activity 8.7, you will be able to answer the questions based on the activity.

Activity 8.7 Class 9 Science Chapter 8

 

You are suggested to study NCERT activity 8.7 class 9 science chapter 8 explanation with a conclusion so that you can attempt questions based on the activity 8.7 class 9 science.

Activity 8.7 Class 9 Science

   ·     At a time when it is cloudy, there may be frequent thunder and lightning. The sound of thunder takes some time to reach you after you see the lightning.

   ·     Can you answer why this happens?

   ·     Measure this time interval using a digital wristwatch or stopwatch.

·     Calculate the distance of the nearest point of lightning (speed of sound in air = 346m/s)

Activity 8.7 Class 9 Science Explanation

The speed of light is much greater than the speed of sound in air. The speed of light is 3× 10⁸ m/s. This is the cause why thunder sounds reach us sometime later than we see the lightning. If we measure this interval of time by stopwatch it comes to nearly 2 seconds.

distance = speed ×time

             = 346 ×2 = 692m

So the sound reaches us later than that of light.

 

Activity 8.7 Class 9 Science Conclusion

This activity infers that the speed of light is greater than the speed of sound.

Related Topics

    1. Activity8.8

    2. Activity 8.6

   3. Solution of chapter 8