Team+2

Potato Cannon Group!!!

Members: Aerik Francis, Alia Ware, Maddy Winslow, Bryan Sulivan, David Nowick



Log Sheet **Research Question:** We will be launching masses of potatoes, from different angles. From this we will know the mass as well as the angle of launch. After the landing of the mass, we will know the distance. Once we find the distance, time, and angle launched, we will be able to determine the best angle to shoot at in terms of the greatest distance.
 * Name(s) || Date || Time || Content ||
 * Aerik Francis || 10-2-08 || 2:00PM || Found links and thought of some things to calculate in our experiment. ||
 * Madeleine Winslow || 11-16-08 || 1:01 PM || Built mini potato cannon, changed thesis slightly ||
 * Aerik,Alia, David, Bryan, Maddy || 10-5-08 and each Sunday since then || 12:00 PM to 3:00 PM || We have met each of these Sundays and formulated plans for the whole experiment (to be posted later), and a plan for the potato cannon (scaled down), building the cannon (11-8-08) and conducting the actual experiment [(11-15-08) results also to be posted with pictures] ||
 * Aerik,Alia, David, Bryan, Maddy || 11-29-08 || 12:00 PM || Made power point. Found online examples of cannons. Going to add pictures of experiment. ||
 * Aerik,Alia, David, Bryan, Maddy || 11-29-08 || 2:30 PM || Potato Cannon Fired multiple times! :) ||
 * All || 11-29-08 || 7:00 PM || Power point presentation complete ||
 * Alia, David, Bryan, Maddy || 12-03-08 || 1:30 PM- 3:00 PM || All of us had fourth off (excpet Aerik) so we completed some final research ||
 * All || 12-04-08 || 1:30 PM - 5:00 PM || Board Completed! Prepared for Presentation as well. ||


 * Hypothesis:**

We believe that the best angle will be 45 ̊ because half of the force will be used to carry the mass up in the y-direction, and the other half will be used to carry it forward in the x -direction. This will cause this angle to have the furthest distance with a fairly fast velocity.


 * Aspect 1: Selecting variables**

In building a mini potato cannon, we are searching for the best angle for the greatest distance. This will then be related back to warfare by comparing our results to the best trajectory for a cannon. This data can be found in an online cannon trajectory simulator. The variable of manipulation will be the angle of trajectory. We will also be formulating predicted distances of the masses from each of the four angles, and comparing the data we find to the theoretical distances.


 * Aspect 2: Controlling the variables**

The variables of this experiment will consist of angle of trajectory, starting velocity, and the distance of mass. The angle of trajectory will be controlled by using a protractor and lining the mini up with the angle wanted. The starting velocity will be controlled by the amount of hairspray sprayed into the combustion chamber. This will be measured by the amount of time that the nozzle is held down (a “spritz”). The distance of mass is dependent upon the angle of trajectory.

Aspect 3:
 * Materials:**
 * Electrical tape
 * Pen
 * Tacks
 * Sparker from BBQ lighter
 * Wire
 * Pill bottle
 * Potatoes
 * Hairspray
 * Safety goggles

1) Research online how to build the cannon. a. Dismantle the lighter and keep the sparker and the wires. b. Take the pill bottle and cut out the bottom. c. Take the shell of the pen and wrap electrical tape around the bottom until it will fit tightly into the pill bottle. Place in pill bottle and tape securely into place. d. Take the tacks and place them close together near the top of the bottle. e. Wrap one wire around one tack, and the other around the other tack. f. Open pill bottle and test sparker. If it works there will a bluish spark between the tips of the two tacks. 2) Secure safety goggles onto head. Place potato into barrel making sure that there is minimal space for air to move around it. 3) Using a set number of sprays, spray hairspray into the combustion chamber and then add air so that there is flammable gas to spark and oxygen so that the spark can burn long enough to launch the mass. 4) Secure the cannon to the protractor at the angle you are testing. 5) Launch the mass, and time how long it is in the air. Locate the mass and measure the distance traveled. Record. 6) Repeat steps 3 – 5 for angles; 0⁰, 30⁰, 45⁰, and 60⁰. 7) Using the data collected, solve for velocity.
 * Procedure:**

Data Collected: 0 || 10.9 meters || 1.09 seconds || 30 || 15.9 meters || 1.27 seconds || 45 || 15.2 meters || 1.17 seconds || 60 || 13.2 meters || 1.53 seconds ||
 * Angle of Trajectory** ||
 * Avg. Distance of Mass** ||
 * Time** ||
 * Time** ||

D/T = V      0 ̊ 10.9m/1.09s= V=10.000 m/s        30 ̊ 15.9m/ 1.27s= V= 12.520 m/s        45 ̊ 15.2m/ 1.17s= V= 12.992 m/s        60 ̊ 13.2m/ 1.53s= V= 8.627 m/s **Applications:** General Rule:
 * With air resistance, the optimal launch angle will go down. This is because more force is needed to shoot the object in the x – direction. Shooting the object up in the y-direction will decrease the horizontal distance because the air will have more time to slow down the object and cause it to drop faster instead of moving out.

Air Resistance: FD = ½ ρ v² CD A


 * Conclusion:**

In our lab, we experimented with hand potato cannon to find out the greatest distance and velocity with a preset angle. We believed that a 45 degree angle would work the best because it would have half of the force in the x direction and the other half in the y direction. To begin, this project relates to warfare due to its similarity to the trajectory of a cannon because both launch an object over a distance at a preset angle using combustion to launch said object. Cannons as we all know have had a great use in numerous battles. The pre-calculated distances provided us with a projected distance in which our own experiment could be compared to as well as a predicted angle to be the most efficient. This optimal angle was projected to be 45 degrees. The longest distance, with the set velocity of 50 m/s, was shown to be 256m at 45 degrees according to the simulation denoted by the graphs in the projected data section of our exhibit. The longest distance, with the set velocity of 12.52 m/s, was shown to be 24 m at 30 degrees according to our own projected data denoted by the table in the projected data section. It was not 45 degrees as we used our own velocities, which are flawed due to our errors. Though the actual velocity is not set in the experiment, it can be seen that 45 degrees should be the most efficient angle. The reason it was not will be discussed in the errors and limitations section of the exhibit. Now, to examine results, there is a great difference between theoretical and experimental data. In our experiment, the angle with the greatest distance was 30 degrees with a distance of 15.9 meters, being closely followed by 45 degrees with a distance of 15.2 meters. This contradicts our hypothesis because we predicted that 45 degrees would be the greatest. It was also predicted that 45 degrees would have the greatest velocity, which proved to be true, because it traveled 12.992 m/s, faster than any other angles tested. There are many limitations and weaknesses that could have caused the errors within our results. For limitations, the first is air resistance. The mass of potato used was very small and would have been affected greatly. Air resistance would have slowed the potato down and lowered the most favorable angle for launching. Another limitation of this experiment was the effect of weather. The potato cannon had to be shot outside, and the weather was always windy and cold, and the coldness could have affected the actual cannon. In fact, it was the most probable cause of the ignition issues we encountered during the experiment. We went through three sparkers to conduct the experiment because each failed to spark after only a few uses. Also, the difference between the theoretical and experimental distances might have been caused by the bouncing of the potato after hitting the ground. Another limitation of this experiment was the ability to maintain the angle of the cannon. Though we had the cannon taped to the protractor there was barrel movement with each fire due to the pressure build up that caused the cannon to launch the potato. This limitations and weaknesses of the experiment could be improved for next time by several solutions. For more accurate results, more trials could be performed. Also, there was great percent error for time, and this could be improved by using a automatic timer that has the capability to stop at the exact moment that the potato mass makes initial contact with the ground. Also, a clearer day should have been chosen for the performing of the experiment (we did not have much of a choice) so that the cannon is least affected by cold temperatures. All in all, even though the experiment sometimes proved to be difficult, it was a challenging a good experiment.

Potato cannon construction links: http://trevorshp.com/creations/cannon.htm http://www.angelfire.com/wy/potato/ http://www.physicsforums.com/archive/index.php/t-5111.html