Acceleration, displacement and velocity describe an object's motion. "Displacement" is used instead of "distance" because velocity has a direction, unlike speed, which has no direction. If you know the initial velocity, the final velocity and the displacement, you can find the average acceleration. The initial velocity is the speed of the object at the start, and the final velocity is the speed at the finish.

Multiply the initial velocity by itself. For example, if the object started at rest, you would multiply zero ft. per second by zero ft. per second to get zero ft. squared per second squared.

Multiply the final velocity by itself. For example, if the final velocity is 10 ft. per second, multiply 10 ft. per second by 10 ft. per second to get 100 ft. squared per second squared.

Subtract the initial velocity multiplied by itself from the final velocity multiplied by itself. In this example, subtract zero ft. squared per second squared from 100 ft. squared per second squared to get 100 ft. squared per second squared.

Multiply the displacement by two. For example, if the acceleration took place over 25 ft., you would multiply 25 by 2 to get 50 ft.

Divide 100 ft. squared per second squared by 50 ft. to get an acceleration of 2 ft. per second squared.