Paul+and+Aaron's+Tre+Bucky

__**A Brief History-**__ The trebuchet is an ancient weapon, designed to hurl heavy projectiles far distances. The trebuchet is said to have begun in China in 300 BC. It has evolved over time into different variations. All trebuchets have counter balances, release arms, and slings; however, some utalize pulley's and weight- shifting systems. The trebuchet is "a remarkable machine that demonstrated a practical application of physics." (1) The applied physics include projectile knowledge for the release point, kinematics, and centifugal force. (2)


 * __Purpose-__** The pupose of this project is to force the students to apply what they know about physics and use it to create a trebuchet. We will be judged not only by how far we are able to throw the projectile ( a christmas ornament), but also taking into account for the length of the arm and mass of the trebuchet. The formula we will be judged on is Percentage = Distance/ Mass x Length of arm.
 * __Materials-__** The material's used in the making of our trebuchet were:
 * 17 x 30 cm sheet of plywood for the base.
 * 2, 31 cm vertical posts.
 * 2, 15 cm suport beams cut at a 45 degree angle.
 * 22 cm metal rod connecting the two vertical posts along with the lever arm.
 * 2 washers.
 * 6 nuts.
 * 32 cm long shaft used for throwing arm and counterweight arm.
 * nail.
 * Duct tape.
 * 2 plastic boxes, each 3 x 4 cms.
 * lead pelets used for counter weight.
 * Screws.

1.) According to the formula, we determined that the most efficient way of recieving a high percentage is having a low weight and short throwing arm. Taking this into consideration, we downsized our project to half of the orginally estimated size. 2.) The base of our project was a 17 x 30 cm sheet of plywood. 3.) Then came the vertical posts which we screwed in through the bottom of the plywood base. 4.) In order for the trebuchet to be stabilized, we added two support beams the were screwed in at a 45 degree angle to the base board. 5.) Two holes were drilled in the vertical posts and a 22 cm metal rod was used as a pivot point. 4 nuts and 2 washers are included on each side of the throwing/ counterweight arm while 2 nuts secure the outside ends of the vertical posts.. 6.) The lever arm is drilled and threaded throw the metal rod. 7.) At the long end a nail was inserted as the eventual "sling" for the projectile. This was accomplished by tying a string to the xmas ornament and wraping a loop around the nail. This sling cuts down in arm length and improved our distance thrown. 8.) After many different attempts, we finally found a counter weight in the form of two 3 x4 cm plastic containers filled with lead pelets. We glued and taped the boxes onto the lever arm.
 * __Procedure-__** The steps involved in constructing our trebuchet were the following:




 * __Test Results-__** After shortening- sling adjustments, our trebuchet began to launch much further than before. However, our results were very inconsistent. Depending on where the sling was located in the plywood and how far the weight of the trebuchet has fallen determined the distance it would throw. Unfortunately the counter weight was losing its grip on the lever arm during our in class marked test. Our P for the in class trial dropped to 5.83, however our trebuchet proved to be significantly better in the trials runs earlier.
 * **Trial** || **Mass (g)** || **Arm Length (m)** || **Distance (m)** || **P=d/m x l** ||
 * 1 || 1.6 || .56 || 5.5 || 6.1 ||
 * 2 || 1.6 || .56 || 5.7 || 6.4 ||
 * 3 || 1.6 || .56 || 5.9 || 6.6 ||
 * 4 || 1.6 || .56 || 5.6 || 6.3 ||
 * 5 || 1.6 || .56 || 5.2 || 5.8 ||
 * 6 || 1.6 || .56 || 5.4 || 6.1 ||
 * 7 || 1.6 || .56 || 5.3 || 5.9 ||
 * 8 || 1.6 || .56 || 5.5 || 6.1 ||
 * 9 || 1.6 || .56 || 5.8 || 6.5 ||

__**Closing Statements-**__ Overall we are very pleased with the results of our trebuchet. Our P rating in the competition was a 5.8, this beat the majority of the competition. Keeping the project simple and light was our goal, it worked out well for us. The key to our success was going without a sling, this double our effeincy. __**Sources-**__ 1.) //Interesting Notes on Trebuchet History, []// 2.) Dan Becker's Trebuchet, [|http://www.prismnet.com/~beckerdo/other/trebuchet.html#theory]