acceleration/deceleration

[devrimci_kürt]

my friend said..In physics, acceleration does not mean speeding up.

right?

 

also, why any change in velocity is called an acceleration..

deceleration is a decrease in speed...why deceleration is not much used?

 

thanks

[D H]

Deceleration is only useful in the context of one dimensional motion, and only with respect to some predefined reference frame. Deceleration is a concept of very limited applicability, and is fully covered by the concept of acceleration in general. Acceleration is any change in velocity.

[Fuzzwood]

Deceleration is simply a negative acceleration.

[swansont]

This is an instance of a lay definition not being the same as the scientific definition.