What does it mean by acceleration and deceleration?

Acceleration and Deceleration-

When we move from one place to another, we have a velocity. Which indicates our rate of progress. For example, if you move towards your destination at 5 meters per second, then we say that your velocity towards the destination is 5 meters/s.

Now, this forward rate can be lower or higher. You need to apply a force to increase or decrease this. As a result, your speed may increase or decrease gradually. If you apply a force to slowly increase or decrease your velocity, i.e. increase or decrease the rate of forward movement per second, then we say you are accelerating. So what do we mean by acceleration? The change in velocity with time is called acceleration.

Naturally, if we calculate the rate of increase of velocity with time, we will get a positive value of acceleration. What we call – positive acceleration. Again if we calculate the decrease in velocity with time we will get a negative value of acceleration. What we call negative acceleration. Then if the value of acceleration is positive, we will understand that the velocity is increasing. And if the acceleration is negative, we will understand that the velocity is decreasing.

You may think, is there a need for a positive or negative sign? If I tell you, the acceleration value while going to my destination was 5 m/s. It can have two meanings. Either my velocity is increasing by 5 m/s per second or my velocity is decreasing by 5 m/s per second. But if I give a positive or negative sign, then it will be understood that my velocity is decreasing or increasing. For ease of expression or understanding, we call negative acceleration as deceleration. That’s why many say to define acceleration, the rate of decrease in velocity with time is called deceleration.