We explain what acceleration is and the formulas used to calculate it. In addition, its difference with speed and examples.
What is acceleration?
We call acceleration in physics to a vector magnitude (that is to say, which has direction) that indicates the variation in velocity according to the passing of time of an object that is in motion. Normally it is represented by the sign a and its unit of measurement in the International System is m / s2 (meters per second squared).
The origin of the acceleration as a concept comes from the studies of mechanics of Isaac Newton (founders of classical mechanics), in which it is ensured that an object will retain its rectilinear and uniform movement (MRU) unless forces act on it. at an acceleration, either positive (increase in speed) or negative (decrease in speed), and either constant (regulate in its action on the body) or not (irregular in its action on the body).
There are several types of acceleration:
- Acceleration postive . When it takes place in the same direction of the movement’s path, adding to its speed.
- Negative acceleration . When it takes place in contradiction to the trajectory of the movement, opposing its speed.
- Medium acceleration . Average acceleration movement of a mobile in time, provided that it occurs in regular units of increase or decrease (uniformly accelerated movement).
The mechanical classical understands the acceleration as a variation of the speed of a body over time , and therefore proposes the following formula: a = dV / dt, where to be acceleration dV the speed difference and dt the time acceleration occurs.
Both variables are understood as follows:
- dV = V f – V i , where V f will be the final speed and V i will be the initial mobile speed. It is important to observe this order to reflect the direction of the 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).
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.