Question

a book rest on a table the force of gravity pulls down on the book with a force of 20 Newtons. what prevents the book from accelerating downward at 9.8 m/s²​

Answer 1

Answer:

ANSWER

sir Newton's third law of motion states that for an action there is always an equal and opposite reaction . These two forces always act on different objects . When a book is kept on a table , weight (gravitational force) of book acts on table vertically downwards and as a reaction of weight , table also exerts an equal and opposite ( upward) force on book .

Answer 2

Book is not pulled down because of an upward force of 20 Newtons acting on it.

Explanation:

• The force of gravity acting on the book is 20 Newtons. Gravitational acceleration exerted on the book due to gravity is $9.8 m/s^{2}$.

• According to third law of motion:

"Every action force acting on a body has an equal and opposite reaction force."

• Newton's third law of motion talks about direction of force and it states that every force comes in pair of action-reaction force.

• So according to third law of motion, when a book kept on the table is pulled down by a force of 20 Newtons, then the table also exerts same amount of force on the book in the opposite direction, which does not let the book fall.

• The table exerts a force of 20 Newton on the book in upward direction and so the book does not fall.