Soaring Straws

The goal of the soaring straws lab was to determine the average height that a straw would travel when propelled by a rubber band, allowing us to calculate Gravitational Potential Energy (G.P.E.) and Elastic Potential Energy (E.P.E.). During the lab, we choose the amount of stretch of the rubber band to shoot the straw and we had three trials for each amount of stretch. The materials we used were one pair of scissors, one rubber band, three plastic straws, a marker, a meter stick, our balance, masking tape, and a empty toilet paper tube. To make the launcher so that we could shoot the straw, we first cut the rubber band. Next, we used the masking tape and taped the two newly cut ends of the rubber band to the top of the toilet paper tube. This way, the straw could be put onto the rubber band so that we could pull it down through the tube and then shoot it straight up into the air. When we did the lab, for the first set of trials, we stretched the rubber band 6 cm and the three trials heights were, 81 cm, 70 cm, and 144 cm, making the average height 98.3 cm (.983 m). For our second set of trials, we stretched the rubber band 11 cm. This made our three trials measurements 230 cm, 233 cm, and 300 cm, and the average height was 2.54 m. Finally, when we did the third set of trials, our amount of stretch was 4 cm. Our heights for the third set were, 95 cm, 98 cm, and 75 cm, making our average height .893 m. In order, the G.P.E. ( which is potential energy that pulls objects back down to earth, solved by mass of the straw times 9.81 for gravity times height) for the three stretches of the rubber band were, 54.96 millijoules (mj), 142.19 mj, and 49.93 mj. E.P.E. is potential energy related to stretch (for example, a rubber band has E.P.E.). What I just stated means that potential energy is energy that is building up to move (once it moves, it's Kinetic Energy). G.P.E. and E.P.E. are related. G.P.E. = E.P.E. since G.P.E. tells how much energy there will be when the straw comes back down to the ground, and equals E.P.E. since that tells how much energy there will be when the rubber band is stretched to send the straw to the height where we figured out G.P.E.

There is an experimental error in of the measurements of how high the straw flew. For the trials that the straw didn't stop at a surface, it was hard to measure how high the straw flew. What would definitely make this better is if I was allowed to use a ladder (a tall one). This would be helpful because if the straw was shot high up into the air, it would be easier to figure out how high it went. Another idea that would improve the lab is if we had 3 meter-long measuring tapes. This would be helpful because if we stood on the ladder, we would be able to pull the measuring tape out all the way we can get it to touch the ceiling and the floor so we could get an even closer height to the actual amount of centimeters the straw flew. Lastly, instead of having three trials, there should be 5 or 10 trials to get more accurate data.