Hey all, I need to build a launcher that is capable of throwing a tennis ball over a 1 meter high wall and hit a target 2 meters away. I realize there are some threads already discussing this, but my question is more based on the type of launcher. Would a trebuchet or a spring powered cannon be more accurate and reliable? We need to build this within a week's time, and the reliability and accuracy of the launcher is more important than the power. The angle also needs to be adjustable, so which of these devices would be easier to adjust the angle on? Thanks for any answers.