Consider a book weighing 5 N that is placed on a table.

The book exerts a downward force of magnitude 5 N on the table due to the force exerted on it by the force.

This force is called the normal force.

## Maxwell’s equations

When a book is thrown down, it is subject to a force that is equal to its weight minus the weight of the air.

This force is called the buoyant force, and it is significant, but difficult to measure.

In order to understand the effect of this force, we need to consider the position of the book on the table and the force that it experiences as it falls.

Maxwell’s equations are very useful in understanding how electromagnetic waves propagate. In fact, these waves are the basis of light.

As such, they are important for understanding light.

The electromagnetic waves that we experience are produced by the movement of charged particles, such as electrons and photons.

One way to understand Maxwell’s equations is to visualize a dielectric material and compare it with an electric field.

The dielectric material would move positive charges to the right and negative charges to the left.

As the strength of the electric field increases, positive charges will move further.

The equations for kinetic energy are easier to understand when the length and time are measured in compatible units.

The units used in particle physics are light seconds and seconds, and they have a similarity to metres and seconds.

## Normal force

A book weighs 5 N. When the book is placed on a flat table, the table exerts a downward force of magnitude 5 N on the book.

The table also exerts an upward force of magnitude _____ on the book.

The normal force acts perpendicular to the book’s surface.

If the book is dropped from the table, the weight of the book exerts a downward force of magnitude 11 N.

The weight also causes the springs inside the mattress to compress.

This forces the springs to exert a normal force on the person.

The same force also causes the invisible “atomic springs” beneath the table surface to compress.

The net force is 4 N.

To understand the normal force acting on an object, we need to understand how this force works. When an object is at rest, the total force acting on it must equal its net force.

This means that the downward force must equal the upward force to keep the object at rest.

Therefore, we should assume that the downward force equals the normal force in order for the book to stay at rest.

This force is important in understanding the relationship between weight and gravity.

A book that weighs 20 kg is weighty, so a normal force exerted by a person of that weight will push it away from the table by approximately 50 n.

## Weight

Suppose a book is resting on a table, and a hand is pushing the book straight down.

You are going to create a free-body diagram to show the forces acting on the book.

Label the forces according to the rules you learned in Forces Tutorial.

Note that the forces acting on a book are the same for a force exerted in the same direction and with the same magnitude, but different for a force exerted on a book that is pushed down.

The force exerted on the book exerts a downward force of magnitude 5 n on the book.

When the book is resting on a table, the force exerted on it by the force is equal to the normal force exerted on it by gravity.

This is the third law of Newton.

## Ground force

Suppose a book weighs 5 N and rests on a table.

What is the downward force on the book and how much force is exerted by the table?

Assume that the force is due to the weight of the book.

The table exerts a downward force of 5 N on the book.

Likewise, a box with a mass of 2.75 kg rests on the elevator floor.