Speech

Good afternoon everyone, my name is Jack Guttenberger, I’m Curtis Mclaughlin, hi I’m Jordan Large, and I’m Nathan Asselstine, and we are here to present our research on tennis ball cannons. Cannons have had a universal place in history, where different forms have existed in completely different countries/society, yet some how have come together even though many of these countries have had no form of communication with each other. It’s through our research of the gas laws that these researches believe through Boyles’ Law, which states at a constant Temperature the pressure and volume of a gas are inversely proportional, that after fuel is poured into our cannon the temperature will cause the pressure to build up and cause the volume to decrease and cause the ball to explode out. This will be similar to a syringe effect where as pressure builds the volume becomes smaller and forces the liquid out, except our cannon will be using temperature causing the Nerf ball to explode out.
Initially, our group roamed around the web searching for ideas and plans for cannons, and in accordance with Boyle’s Gas Law, which states that at constant temperature the pressure of a gas is inversely proportional to the volume, we were led to create a cannon with a small volume. Furthermore, after viewing the research we created a graphic organizer in which we had many ideas, but one prevailed over all: a cone shaped funnel with a top chamber that would hold the ball. This idea seemed to be the best of the beginning ideas considering the fact that it would minimize volume, maximize pressure, and channel that pressure into one spot: the ball. In accordance with Boyle’s Gas Law, our group knew that if we were to decrease the volume we would inversely increase the pressure which was why we made a small bottom chamber to create a stronger propellant. Creating a stronger propellant would be the deciding factor in how far our cannon shot the ball which is why we researched the volume to pressure ratio. In conclusion, our group saw through meticulous research, that Boyle’s Gas Law was a huge factor in the decision of our cannon making because we knew from this law that the smaller the volume the more pressure was exerted.
Afterwards, we began the construction of our cannon, basing the model on our ultimate construction plans. With two thin triangles cut out of each side of one tube, we were able to wrap the ends around to form a cone, taping the funnel shut. With the use of the funnel we hoped to maximize pressure build-up and minimize volume. Secondly, we cut the base from one tube to form the base of our cannon and slid the hollow tube over our bottom funnel chamber, finalizing the creation of our barrel, and leaving the ring as the exit point to reduce friction. With the construction of our barrel thusly we attempted to maximize build up in the funneling chamber and hopefully hit the Nerf ball with optimal, instantaneous force. The construction of our cannon had been completed, and we hoped that the pressure would be enough to launch the Nerf ball a good distance.
We think these results occurred, because the amount of pressure was decreased from the cone fixture within the cannon. In accordance with Boyle’s Gas Law, the amount of volume we had was too large in essence of the ratio of pressure to volume.

Student Product

http://nasselstinecannon.blogspot.com/

Firing and Reflection

When we fired our cannon, as Group 3, our cannon did not fire. Instead, our cannon instantly filled with smoke and the ball began to burn. Our cannon heated up, but did not melt or deform.

Another group, Elsie, Jermaine and Sarah, fired their ball 20 ft. When the cannon went off, there was a large bang, and the end of the barrel soon began to melt. If the volume of the cannon had been less, our cannon's pressure may have built up better.

The ring around our barrel enabled friction to be minimized, and seemed to have prevented the barrel from melting.