To calculate the mean accelerating force (MAF), you need to know the initial velocity (vi), final velocity (vf), and the total time (t) taken for the change in velocity. The formula for MAF is:

MAF = (vf - vi) / t

Here's how you can calculate MAF using this formula:

1. Determine the initial velocity (vi): This is the velocity of the object at the beginning of the time interval.

2. Determine the final velocity (vf): This is the velocity of the object at the end of the time interval.

3. Calculate the total time (t): This is the duration over which the velocity changes.

4. Substitute the values of vi, vf, and t into the formula: MAF = (vf - vi) / t.

5. Calculate the result: This will give you the mean accelerating force acting on the object during the specified time interval.

Remember, MAF is a vector quantity, so it has both magnitude and direction. The direction of MAF is the same as the direction of the net force acting on the object.