# The greatness of kinematics

To study kinematics, that is, the description of the movements, we need to take into account some essential quantities, which are:

## Time interval

All the movements that we will study will happen from a certain moment, which we will call the initial moment and represent by t.

The time that elapses between two certain moments we call time interval. We represent the time interval by . Its unit in the international system is the second.

 We can mathematically represent the time interval by:

## Position

Have you ever noticed those little signs on the roadside? They indicate the mileage, record the position of the car and allow you to locate on the road.

Position of a furniture is its location in relation to a certain origin .

We represent the position by S. Its unit in the international system is the meter (m).

## Displacement

Suppose a person left kilometer 4 and is now at kilometer 8. His position varied 3 kilometers, right?

Your starting position, represented by s0, is 4 km. Your final position is s, and worth 8 km.

The difference between two positions of a furniture is called displacement.

 We represent displacement by . Its unit in the International System is meter (m), and its mathematical representation is:

Thus, the displacement of the person in question was as follows: