1. The problem statement, all variables and given/known data While someone is accelerating upwards but before the body leaves its feet, is there a net force? The person will eventually leave the ground. 2. Relevant equations ƩFy = 0; or does ƩFy = ma? 3. The attempt at a solution I pretty sure that the latter is true, this is so frustrating because I can see how either is true. ƩFy = 0 makes sense because the feet relative to the ground are not accelerating or even moving. But, I can also see how it should me ƩFy = ma because there is a "stationary" acceleration that the feet are exerting on the ground while the body accelerates up.