Physics launcher project?

Question

I have to build a launcher/catapult/slingshot contraption for physics, and what I've done so far hasn't been working. I can only use 10 rubber bands, 5 paperclips, 10 popsicle sticks, and 2 paper towel tubes. The launcher must be freestanding. I can only use tape and glue to hold it together, and it has to launch a ping pong ball 4.5 meters. I'm pretty sure the best way is to build some type of slingshot, but I can't get the paper towel tubes to stay up, even with tape/glue. Also, I can't figure out any ideas on how to make place for the ping-pong ball to sit if I were to do a slingshot. Does anyone have any ideas on how to make this work?

Answer 1

First, use the paper towel tubes as the foundation. You need a wide base if it has to be free standing and still shoot. Second, use the paper clips to form a mesh spoon shape to cup the pin pong ball. You should only need about 3 paper clips for that. Make sure when you make the spoon, the ends of the paperclips come out in the same direction(like a real spoon does for the handle.) Use this end to glue and then tape to a popsicle stick. Use the popsicle sticks to form a lever (like a seesaw) with the spoon on one end, and the rubberbands on the other. You have 10 sticks and it shouldn't take that many to make a lever. Use the access sticks to make a frame between the papertowel tubes, and attach your lever in the center with the rubber bands attached to the frame of popsicle sticks. Note: make sure the angle of the lever is between 30 and 45 degrees for best results.