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Karnataka Board PUCPUC Science Class 11

Consider a Book Lying on a Table. the Weight of the Book and the Normal Force by the Table on the Book Are Equal in Magnitude and Opposite in Direction. is this an Example of Newton'S Third Law? - Physics

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Question

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

Short Note

Solution

No, this is not an example of Newton's third law. According to Newton's law, if a body A exerts a force on body B, then B exerts a force on A equal in magnitude and opposite in direction. The forces act on different bodies. So, the normal by table on the book is action and the reaction pair is the force on a table by the book. Weight is due to the force of the earth on the book, not due to the table. Hence this is not an action-reaction pair
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Chapter 5: Newton's Laws of Motion - short answers [Page 77]

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HC Verma Concepts of Physics Vol. 1 [English] Class 11 and 12
Chapter 5 Newton's Laws of Motion
short answers | Q 14 | Page 77

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