Activity 12.3 Class 8 Science Chapter 12 Solution

Activity 12.3 Class 8 Science Friction

 In this post, you will find NCERT Science Class 8 Chapter 12 Friction activity 12.3 and after reading this, you can understand the concept of 'Friction' in daily life.

You are suggested to study NCERT activity 12.3 class 8 science explanation with a conclusion so that you can attempt questions based on activity 12.3 class 8 science.

Activity 12.3 Class 8 Science

   ·     Make an inclined plane on a smooth floor, or on a table.

   ·     You may use a wooden board supported by bricks, or books.

   ·     Put a mark with a pen at any point A on the inclined plane.

   ·      Now let a pencil cell move down from this point.

   ·      How far does it move on the table before coming to rest?

   ·     Note down the distance.

   ·     Now spread a piece of cloth over the table.

   ·      Make sure that there are no wrinkles in the cloth.

   ·     Try the activity again.

   ·     Repeat this activity by spreading a thin layer of sand over the table.

   ·      Maintain the same slope throughout the activity

      

 Activity 12.3 Class 8 Science Chapter 12 Solution

Observation and Explanation 

 

Case I

When a pencil cell let to be rolled on the inclined plane from point A, it covers a distance say 30 cm. , on the smooth surface of a table.

Case -II

Now we spread a cloth over the smooth surface of the table and let the pencil cell roll from point A at an inclined plane, this time pencil cell covers distance of 20cm (lesser than the previous situation).

Case -III

Now we spread a layer of sand over the smooth surface of the table and let the pencil cell roll from point A at the inclined plane, this time pencil cell covers a distance of 5 cm.

We can see the distance covered is minimum in the case when a thin layer of sand is spread over the table.

It so happened because the rough surfaces provide high friction. This concept has also been explained in activity 12.2.

Conclusion 

This activity shows that friction depends upon the nature of the surface in contact.

Frequently asked question

1. In which case is the distance covered the minimum in activity 12.3 Class 8 Science?

Ans. – The distance covered is minimum in the case when a layer of sand is spread over the table.

2. Why is the distance covered by the pencil cell different in activity 12.3 class 8 science?

Ans. – The distance covered by the pencil cell is different every time because the applied friction force is different in each case. Friction depends upon the nature of the surface.

3. Does the distance covered depend on the nature of the surface on which it moves?

Ans.-  yes, the distance covered depends on the nature of the surface on which it moves.