Hello: I'm stuck on this following problem. A spring gun, held horizontally 1.6 meters above the ground, fires a 0.07 kilogram ball so that it lands a horizontal distance of 2.3 meters away. If the gun is pointed straight up, and the same ball is fired, how high (in meters) will it rise? I know that: (Potential gravity) = (mass) x (gravity) x (height) Also: (Spring potential) = (1/2) x (k) x (x^2) I'm not really sure how to tie the two together... Also, I'm thinking of using the conservation of energy formula: (final kinetic + final potential gravity + final spring potential) = (initial kinetic + initial potential gravity + initial spring potential) but I don't know how to get to the spring constant (k) with the given information in this problem. Any help would be appreciated.