You buy a plastic dart gun, and you wnt to find its max. horizontal range. you shoot the gun straight up, and it takes 4s for the dart to land back at the barrel. What is the maximum horizontal range of your gun? I got the initial velocity, which is 19.6 m/s. I know I have to incorporate vectors. The initial velocity in the horizontal direction is 19.6m/s (cos x) and in the vertical direction it is 19.6m/s (sin x). Assuming x is the magnitude of the angle. I know that the total displacement in the vertical direction is 0. And now I am stuck...How do I proceed from here? Please help!! Thanks so very much.