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 means that acceleration tells you how quickly an object's velocity is increasing or decreasing. The equation shows that acceleration is calculated by subtracting the initial velocity from the final velocity, and then dividing that difference by the time it took for the velocity to change.

Units:

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

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

* Time (t) is measured in seconds (s).

Example:

Imagine a car starts from rest (v_i = 0 m/s) and accelerates to a final velocity of 20 m/s in 5 seconds. To calculate the acceleration:

* a = (20 m/s - 0 m/s) / 5 s

* a = 4 m/s²

Therefore, the car has an acceleration of 4 meters per second squared.

Important Notes:

* If the initial velocity and final velocity are in the same direction, acceleration is positive.

* If the initial velocity and final velocity are in opposite directions, acceleration is negative.

* If the velocity is constant, acceleration is zero.