Question

Newton's third law explains that for every action force there is an equal and opposite reaction force. In the image below, the arrow represents the force of Earth pulling down on the book. This is also called the force of gravity.



Based on Newton's third law and the force represented by the arrow, what is the reaction force in this scenario?
A.
The force of the book pulling down on the table.
B.
The force of the table pushing down on Earth.
C.
The force of the book pulling up on Earth.
D.
The force of the table pushing up on the book.

Answer 1

C. The force of the book pulling up on Earth.

Explanation: Newton's third law pairs forces between the same two objects. If Earth pulls the book downward (gravity), the reaction is the book pulling upward on Earth with equal magnitude. The table's forces are different interaction pairs (book–table), not the gravity pair.