Can you have negative acceleration?

[Josh S Thompson]

Someone told me there is no such thing as negative acceleration and I did not believe them.

They said its called deceleration and is not considered negative acceleration.

Is this true and why?

 

[Drakkith]

Acceleration is a vector. That means it has a magnitude and a direction. If we have an acceleration vector pointing in a positive direction, as determined by our coordinate system, then the acceleration is positive. If it points in a negative direction as determined by our coordinate system, then the acceleration is negative.

Deceleration is a not formally used in science. Any change in velocity is simply called acceleration, regardless of whether the acceleration is positive or negative. In every day language deceleration is used to describe an acceleration that slows your speed down (speed is the magnitude of velocity). This means that deceleration is simply acceleration that points in the opposite direction as velocity.

In short, yes, there is such a thing as negative acceleration.

 

[Josh S Thompson]

Acceleration is a vector. That means it has a magnitude and a direction. If we have an acceleration vector pointing in a positive direction, as determined by our coordinate system, then the acceleration is positive. If it points in a negative direction as determined by our coordinate system, then the acceleration is negative.

Deceleration is a not formally used in science. Any change in velocity is simply called acceleration, regardless of whether the acceleration is positive or negative. In every day language deceleration is used to describe an acceleration that slows your speed down (speed is the magnitude of velocity). This means that deceleration is simply acceleration that points in the opposite direction as velocity.

In short, yes, there is such a thing as negative acceleration.

Agreed,
I knew there is negative acceleration