Question

Consider a book lying on a table. The weight of the book and the normal force by the table on the book are equal and opposite. Is this an illustration of Newton's third law?

Answer 1

When a book is lying on the table,

1. The weight of the book on the table exerts a force due to gravitational pull.
2. The normal force by the table on the book is due to the table.
4. Therefore, these both forces cannot be action-reaction pairs as action-reactions pair occur on two different bodies.
5. But here, both the forces are acting on the book.
6. Hence, it cannot be an illustration of Newton's third law.

Hence, a book lying on the table cannot be an illustration of Newton's third law.