Acceleration is a vector that is described by both direction and magnitude and it helps you to evaluate the amount of change of velocity in a specified amount of time.

The mathematical formula that helps you to evaluate the acceleration is the following, such that:

`a = (Delta v)/(Delta t)`

`Delta v` represents the changein velocity and it can be evaluate subtracting the initial value of velocity from the final value of velocity, such that:

`Delta v = v_f - v_i`

`v_f` represents the final velocity

`v_i` represents the initial velocity

`Delta t` represents the change in time and it can be evaluate subtracting the initial time from the final time, such that:

`Delta t = t_f - t_i`

You may evaluate the acceleration at any time differentiating the velocity equation with respect to time.

`a(t) = (dv)/(dt)`

Acceleration is defined as the change in velocity with respect to time.

When looking at the units for acceleration (m/s^2), this makes sense because if velocity is measure in m/s, then velocity with respect to time is m/s/s or m/s^2.

Again, acceleration is measured in m/s^2.

Remember than because velocity includes direction and speed, acceleration not only refers to the change in speed, but also the change in direction.

Hence, a particle traveling in a circle at a constant velocity will have a changing acceleration, because it's direction is always changing.

Acceleration is change in velocity(final velocity-initial velocity) over time(final time-initial time)

The best definition for acceleration would be change in velocity over time.

delta v= change in velocity= final velocity-initial velocity

delta t=change in time= final time-initial time