Activity 12.4 Class 8 Science Chapter 12 Solution

Activity 12.4 Class 8 Science Friction

 In this post, you will find NCERT Science Class 8 Chapter 12 Friction activity 12.4 and after reading this, you can understand the concept of 'Friction' in daily life.

You are suggested to study NCERT activity 12.4 class 8 science explanation with a conclusion so that you can attempt questions based on activity 12.4 class 8 science.

Activity 12.4 Class 8 Science

 

   ·     Take a few pencils that are cylindrical in shape.  Place them parallel to each other on a table.

   ·     Place a thick book over it.

   ·      Now push the book.

   ·     You observe the pencils rolling as the book moves.

   ·      Do you feel it easier to move the book in this way than to slide it?

   ·     Do you think that resistance to the motion of the book has been reduced?

   ·     Have you seen heavy machinery being moved by placing logs under it?

       

 Activity 12.4 Class 8 Science Chapter 12 Solution

Observation and Explanation 

When the book placed over the pencils is pushed, it moves easily and the pencils also roll. Rolling a book is easier than sliding the book over a surface.

When one body rolls over the surface of another body, the resistance to its motion is called rolling friction.

 Rolling reduces friction. In day-to-day life, we can see heavy machinery moved over rollers.

 

Conclusion 

This activity shows that rolling friction is smaller than sliding friction.