I am in middle school and we are doing a catapult projectile lab. The question is, using knowledge of force, motion and projectiles, can a catapult be built to accurately project a marshmellow toward a designated target. We have to change the angle of release and measure average flight time and distance and then come up with the average speed and then the force required at each angle. The question I have is how to even go about writing a hypothesis. What are they looking for????

Since this is not my area of expertise, I searched Google under the key words "projectile trajectories" to get these possible sources:

http://hyperphysics.phy-astr.gsu.edu/Hbase/traj.html
http://www.glenbrook.k12.il.us/gbssci/phys/Class/vectors/u3l2b.html
http://www.cut-the-knot.org/Curriculum/Geometry/DupontGarden.shtml
http://www.cs.utah.edu/~zachary/isp/applets/Cannon/Cannon.html
http://www.glenbrook.k12.il.us/GBSSCI/PHYS/Class/vectors/u3l2c2.html

Although this material seems a little complex for middle school, I hope it helps. Thanks for asking.