1. The problem statement, all variables and given/known data If a long jumper at the top of his trajectory is moving at 6.5 m/s (horizontally) and his centre of mass is 1.1m abover where it was when he launched into the jump, how fast must he have been moving when he launched? 2. Relevant equations Vx = Vox + ax*t 3. The attempt at a solution In all texts i look at they say that the initial velocity should be the same as final velocity in the x axis but that isnt the correct answer for the question in the text. Thanks for any help.