Can anyone explain to me why (when air resistance is ignored), that 45° angle is the ideal angle for the longest range? Is it because if it is over 45° then gravity will be acting on it longer therefore will be dragged down sooner? Also as "u cos >45" produces a lower exit velocity(horizontally)? But what if it is below 45? Then the exit velocity is greater than at 45, but then does the greatest height have something to do with it does travel as far as when the angle is closer to 45. Also when air resistance is taken into account, there is a force acting in the opposite direction to the velocity, so obviously the range will not be as great, however, how come there is a bigger difference between the ideal and actual ranges at angles above 45 than below? Is it due to f=ma and the fact that the projectile is travelling more in the vertical direction and that the exit velocity would not be as great(horizontally) so it does not take as much force to slow it down than angles lower than 45?