Question

12.

Answer 1

The Earth's gravitational pull and the table's force are of equal magnitude and in opposite directions, they balance each other.

Explanation:

A book placed on a surface have two forces acting on it which are, a force that pulls it toward the ground in a downward direction, that is gravitational pull and a second which is acted on the book on upward direction making a balance on the object.

This follows Newton’s third law of motion that states every action has an equal and opposite reaction. $\bold{\mathrm{F}_{\mathrm{A}}=-\mathrm{F}_{\mathrm{B}}}$