Hi all! I have entered a a water rocket competition. The rockets in this competition will be launched at 60 psi. We have to launch the rockets horizontally and to hit a round landing site 100 meters(approximately 328.084 ft) away and 30 meters (approximately 98.4252 ft) wide. I am not good at physics, so can anyone help me? How much should my whole rocket should weight to hit the center of the target? And also, how much water should i fill in?