why a book on a table is not considered a action-reaction pair although normal force and weight(due to gravity or gravitational force of earth)are equal and opposite?

Asked by abinash.gupta003 | 17th Aug, 2016, 07:14: PM

Expert Answer:

There are two forces acting upon the book. These forces are: Earth's gravitational pull which exerts a downward force and the push of the table on the book which is directed upwards on the book. The book exerts action force on the table equal to its weight in the downward direction is the action force and the table exerts an equal force (reaction force) on the book in the upward direction.

These two forces acting on a book are of equal magnitude and in opposite directions, and hence they balance each other. Thus, the book is said to be in equilibrium.

It is obvious that the "action" of the book acts on the table top on which it is lying and the "reaction" of the table top acts on the book. Thus, action and reaction act on two different bodies.

Answered by Yashvanti Jain | 18th Aug, 2016, 11:41: AM

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