1. The problem statement, all variables and given/known data A projectile has a time of flight 7.5s and a range 1200m calculate (a) its horizontal velocity (b) Its maximum height (c) the velocity witch which it is produced I take ay as -9.8ms-2 2. Relevant equations r = uxt dy = uyt + (ayt2/2) vy2 = uy2 + 2ah ux2 + uy2 = u v = u + at 3. The attempt at a solution I hope I am the correct a) r = uxt ux = r/t ux = 1200/7.5 ux = 160m .: Initial Horizontal Velocity is 160m b) dy = uyt + (at2/2) dy = 0 (Total vertical displacement is zero) 0 = 7.5uy - 275.625 7.5uy = 275.625 uy = 36.75 vy2 = uy2 + 2ah vy = 0 0 = 1350.5625 - 19.6h 19.6h = 1350.5625 h = 68.90625 ... .: Maximum height is 68.91m-1 c) ux2 + uy2 = u (160)2 + (36.75)2 = 26950.5625 u = 164.1662648 ... .: Initial Velocity is 164.17ms-1 v = u + at v = (164.1662648) + (-9.8)(7.5) v = 90.6662648 ... .: Final Velocity is 90.67ms-1 Ya ?