I have to find the vertical displacement of a potato shot out of a potato launcher (Gr. 11 Physics assignment). It would make sense (and make this easier) to assume that the potato went straight up and down and I am allowed to assume that air resistance is negligible. My main problem is proving algebraically that the upward motion and downward motion are equal in terms of time. If they aren't equal I guess I need to start my thinking all over. :uhh: Here are my givens if they are needed: m = 249g Δt = 4.15s Any help would be appreciated. Thanks.