# Acceleration

We explain what is the acceleration and the formulas used to calculate it. In addition, its difference with speed and examples.

### What is the acceleration?

We call physical acceleration **a vector magnitude** (that is, endowed with direction) that the variation in the speed according to the time elapsed of an object which is in motion. Normally it is represented with the sign *to* and its unit of measurement in the International System is m / s2 (meters per second square).

The origin of the acceleration as a concept **comes from the studies of Isaac Newton** (founders of classical mechanics), in the that it ensures that an object will retain its rectilinear and uniform motion (MRU) unless it is on l, Whether positive (increase in speed) or negative (decrease in speed), and either constant (regulate in its action on the body) or not (irregular in action) over the body).

There are several types of acceleration:

**Positive****acceleration**. When it takes place in the same direction of the movement's path, adding to its speed.**Acceleration negative**. When it takes place in contradiction to the trajectory of the movement, opposing the speed of it.**Acceleration medium**. Average of the accelerating movement of a mobile in time, provided it occurs in regular units of increase or decrease (uniformly accelerated movement).

See also: Kinematics.

### Acceleration Formula

Classical mechanics understand acceleration as **a variation of the velocity of a body in time**, so proposes the following formula: a = dV / dt, where *to* ser be acceleration, *dV* the difference in velocities y *dt* The time at which the acceleration occurs.

Both variables are understood as follows:

**dV****=****V****f****– V****i**, where*V**f*be the final speed and*V**i*the initial speed of the mobile. It is important to observe this order to reflect the direction of acceleration.**dt****=****t****f****- t****i**, where*t**f*will be the final time and*t**i*the initial time of the movement. Unless otherwise stipulated, the initial time will always be 0 seconds.

On the other hand, according to Newton's studies, given a body of constant mass (m), there is a relationship of proportionality with respect to the force that is applied to the object (F) and the acceleration obtained from it (a), and That is stated as follows:

F = ma

That way, we can calculate the acceleration with the following formula:

a = F / m

All this according to Newton's second Law or Fundamental Law of Dynamics.

### Speed and acceleration

Speed and acceleration **are two different concepts** . Its difference is that the first refers to the amount of distance that a body travels in a given unit of time (so it is measured in Kmph, for example) while acceleration has to do with the variation of said speed in a object, whether or not it moves (Initial speed = 0).

### Acceleration Examples

Some examples of acceleration could be:

- The takeoff of a space rocket, which gains greater speed as it rises. It is possible to calculate your acceleration if we have the force of the thrust that your fuel gives you and the total mass of the rocket.
- A train that stops, experiences a negative acceleration when it is about to approach the station, which can be calculated using the initial and final speeds corresponding to each passing moment.
- A ball is resting on the ground, before a child kicks it. The ball will reach a certain speed in its displacement, after it has accelerated from 0 to said average speed and then it will slow down again until it returns to rest.