a = (v_f - v_i) / t

where:

* a is acceleration

* v_f is final velocity

* v_i is initial velocity

* t is time

Explanation:

Acceleration is the rate of change of velocity over time. This equation shows that acceleration is calculated by finding the difference between the final velocity and the initial velocity, and then dividing that difference by the time it took for the change to occur.

Units:

* Acceleration is typically measured in meters per second squared (m/s²).

* Velocity is measured in meters per second (m/s).

* Time is measured in seconds (s).

Example:

If a car accelerates from rest (v_i = 0 m/s) to a final velocity of 20 m/s in 5 seconds, its acceleration can be calculated as follows:

a = (20 m/s - 0 m/s) / 5 s = 4 m/s²