Ping Pong Ball Launcher

Group: Jenny Pauk and Courtney Hoffman

Goal: To create an idea for a launcher that can project our ping pong ball the farthest. To utilize the maximum distance using angles and rubber band force.

Plan of Attack: We started out with an online idea for our launcher. Once we actually started developing a design it changed drastically from our original idea. We used the long skinny rubber band. Jenny and I decided to create as close to a 45 degree angle as we could because we remembered the website we had taken notes over, and the maximum distance was reached at 45 degrees. We had a few ideas for how to release the rubber band, and we finally decided on a turning dowel. The dowel has a hook stuck in it and you turn the dowel to release the rubber band. The board that holds everything together was at approximately a 46 degree angle. We experimented putting books under the edge to change the angle, and we ended up using a calculus book to change the launcher to 30 degrees. 

Expected Results: Our expected results were probably 40 or 45 feet. We got our launcher to go 50+ feet at one point for a test run, but we could never replicate that. We also got 35-45 feet consistently, but didn't get that for our actual result for our real launches. 

Actual Results: Our actual result was 26 feet. Our launcher kind of let us down and we really don't know what was the cause of not getting as good of results on launch day. We tried changing the angle, changing our rubber band, and changing the position of the ping pong ball a few times, but nothing seemed to work in our favor. We didn't have much consistency with our launcher and it was kind of frustrating.

Error Analysis: The second day the farthest we could go was 26, but the first day we were able to go a lot farther. We don't really know what happened and we tried a different rubber band, but it didn't work. We also didn't have that much force which was detrimental to our launcher.
Lessons Learned:It is hard to get consistency with a rubber band ping pong ball launcher. There are so many factors that go into the launcher. Some of the factors are: the type of rubber band, the angle of the launcher, the friction between the ball and the launcher, and the force behind the rubber band. Our force wasn't very high, it was only 26, so that was a big issue.

Conclusions: Going into this project, the goal was to build the ping pong ball launcher that could shoot the farthest. We did not make one that can shoot the farthest, but we learned a lot about physics and using what we know now, we could make a better launcher. Our force was only 26 and Julian (who's launcher got second) had a force over one-hundred. We also found our initial velocity and if that was higher our launcher could have gone farther. We found our initial X velocity (13.8) first using the time (1.89) and delta X (26), but we wanted the overall velocity. When we found the X and Y velocities previously we used the overall velocity and multiplied by the cos or sin of the angle. So we worked backwards using our angle (30 degrees) and X velocity. We set up something that looked like this: 13.8=(overall velocity)(cos30). Then we divided and came up with 15.9 as our overall velocity. If we had more force, a higher velocity, and more consistency we would have had a better launcher, but overall it was a fun project and we learned a lot.