Effect of Counterweight Mass on the Range of audCounterweight Trebuchet

摘要

Although it has none or little use today, trebuchets were essential siege weapons inudmedieval warfare. Especially the counterweight trebuchet is capable of throwingudmassive objects at great distances. In this investigation, it was intended to examine audcounterweight trebuchet’s performance over increasing quantity of mass that theudcounterweight part contains. A mini trebuchet is built out of wooden planks, using audsimple mechanism to project a small metal ball. After controlling all the other factorsudthe experiment was carried out to observe the ball’s range with differentudcounterweight masses. When the data recorded was plotted on a graph, a linearudchange was observed with a slope of 3.208 m/kg for a 130.0 g metal spherical ball.udAccording to the hypothesis, a linear change was estimated indeed, only with a slopeudof 4.630 m/kg. This ratio of error, approximately 30.71%, can be ignored, sinceudestimations on the range were based on a frictionless system, not to mention it’s notudpossible to construct a 100% efficient system or even close to that in terms ofudthermodynamics. Correlation coefficient of the experimental results is 0.9964, whichudshows that the results are consistent within the experiment itself. On the other hand,udefficiency of the trebuchet gradually decreased with increasing counterweight mass,udindicating that the system has an energy capacity and the range would rise only up touda point if further investigation was done. As a conclusion, this experiment provides audbrief understanding of principals of pre-gunpowder siege units in general, as well asudscopes the particular mechanisms of counterweight trebuchets and methods toudoptimize a trebuchet in order to maximize its energy efficiency.