Okay, here's the deal. 2nd day back at college and I pretty much have forgot most everything Physics related already :uhh: Had a very easy assignment today in one of my engineering classes to take two dowels and a bunch of rubber bands and build something that could launch/throw a tennis ball from atop a terrace towards a point on the ground below (goal to get as close as possible, if not a bulls-eye). So, you say, that's elementary stuff, what's the problem? Here ya go: I have: -the mass of the ball -the distance it traveled in 4 different trials -the times it traveled -the actual distance from the terrace to the target (x) -the height of the terrace (y) I need to write and use equations to: 1) predict where the ball will land (assuming we hadn't actually launched it) 2) determine the effective spring constant for the system (in this case, two strings of rubber bands) 3) in addition to, I guess, finding the initial velocity using what info. I have So, while this is, in essence, so easy it hurts, I'm brain dead right now and just need to know how to get/do #1,2,3 based on what I already have (ball mass,travel/height distances, and times). Thanks!