Why does a book remain at rest on a table?

A book remains at rest on a table due to the balance of forces acting upon it, specifically gravity and the normal force.

In more detail, the reason a book remains at rest on a table is due to the principles of Newton's First Law of Motion, also known as the Law of Inertia. This law states that an object at rest will stay at rest, and an object in motion will stay in motion, unless acted upon by an external force. In the case of the book, there are two main forces acting upon it: the force of gravity pulling it downwards, and the normal force from the table pushing it upwards.

The force of gravity is a result of the mass of the book and the acceleration due to gravity. It acts downwards, towards the centre of the Earth. On the other hand, the normal force is the force exerted by a surface to support the weight of an object resting on it. It acts perpendicular to the surface, in this case, upwards from the table.

When the book is at rest on the table, these two forces are in equilibrium, meaning they are equal in magnitude but opposite in direction. This balance of forces results in a net force of zero. According to Newton's First Law, since the net force acting on the book is zero, the book will remain at rest.

Furthermore, it's important to note that if an additional external force was applied to the book, such as a push or a pull, the book would move. This movement would continue until another force, like friction or a hand stopping it, acted upon it to bring it back to a state of equilibrium.

In conclusion, the book remains at rest on the table due to the balance of forces acting upon it. The force of gravity pulling it downwards is balanced by the normal force from the table pushing it upwards, resulting in a net force of zero and keeping the book at rest.