How to calculate GameObject's velocity from AddForce.

Hi all,

I have some questions for Unity physics. I want to know about GameObject's the velocity with the AddForce.

for example,
If a GameObject was added Rigidbody. ( for example a ball ) And I did Addforce some value(Force-Vector3) to this GameObject. ( about y-4000 ) and I checked this GameObject's velocity(Vector3) in Fixedupdate(). I confirmed the velocity in first-next Frame. ( about y-24 )

I don't know how to calculate velocity y - 24 from AddForce y - 4000.

please let me know. thanks.