Hello!
When the final velocity is less than the initial velocity, this is deceleration
<h2>Why?</h2>Acceleration is defined as the physical magnitude that measures the change in velocity with time. The units to express acceleration are speed over time.
The equation for acceleration is:
Where: a=acceleration, v=final velocity, vo=initial velocity, t=final time, to=initial time.
If the final velocity is less than the initial velocity, then the acceleration is negative, and that is called deceleration. An example of this is when a car brakes.
Have a nice day!