you set up a 40cm long marble launcher that it sits at a 30 degree to horizontal on the edge of your table, which is at a height of 76cm above the floor. You fellow group member positions the retort stand 40cm away from the edge of the table. If you launch the marble by following it to fall form rest at the top of the launcher, at what height should your teammate position the Dixie cup on the retort stand, such that it will catch the marble