This simple experiment will show the power of frictional force when several sheets of paper are overlapped.
2 notes or exercise books with approximately the same number of pages.
On a table or flat surface, open the 2 books to their last pages and overlap their back covers.
Then take the next pages and overlap each one. Continue doing this until you reach their front covers.
Tell a friend to hold the binding of one book, and you hold the other one.
Try to pull the notebooks apart this way and see what happens.
The books should be very difficult to pull apart.
The surface of paper appears smooth to the naked eye. But when viewed under a microscope it has a rough surface. When 2 or more paper surfaces come in contact, the surfaces interlock due to frictional forces. The frictional forces existing between the paper surfaces makes it difficult to pull the notebooks apart.