[填空题]
You buy a plastic dart gun, 1 za+5o*e2 ubbvsc( vaand being a clvlqa5,8t hhj6 amvm* .ever physics student you decide to do a quick calculation to find its maximum horizontal range. You shoot the gun straight up, and it takes 4.0 s for the dart to land back at the barrel. What is the maximum horizontal range l8h,6hqav j a*5.v mtmof your gun?
