Thursday, October 21, 2010

Trebuchet Fun For Everyone!!

Our next project in physics was building a trebuchet. A trebuchet is a medieval catapult for throwing heavy stones through walls when in battle. Some believe the trebuchet was developed from the stave sling, which was a powerful sling that was used for mass bombardment. The trebuchet was first introduced to England in 1216 during the Siege of Dover. Louis the Dauphin took the trebuchet across the Channel and attacked the Dover Castle walls successfully. Master James of St. George, who was Edward I's chief engineer, built the Warwolf which is considered to be one of the most powerful and famous trebuchets in the world.

We built our trebuchets and hoped things would work out well when we experimented with them. We tested ours out the night before and the trebuchet was launching straight up so we added more weight. Once we added the weight, the trebuchet began to launch forward. We had about 75 lbs. on the trebuchet and decided to hope for the best when we tested on Monday. Monday in class, we added more weight but when we launched it, the object would only go about 20 or 25 feet each time. The added weight wasn't making much of a difference. Then, when we were about to launch again, we looked and we realized the weights were grazing against the ground. The weights were causing friction against the ground and it was keeping the objects from going 50 feet when we would launch. By the time we realized this, it was the end of the period so we decided to bring a cinder block the next day. Tuesday in class, we put the weights on the cinder block. This made it easier to tie the weights higher and tighter. Finally, after a couple tries on Tuesday, our pumpkin went about 47 feet!! We were all very excited because we accomplished our goal for the trebuchet!  

I learned that friction was affecting our trebuchet from going the 50 feet. Also gravity pulls the weights to the ground when the arm is released. The arm creates an arc that travels when the object travels through the air. Velocity is another part of physics that played a role in the trebuchet. The distance that the object traveled and the speed it was traveling through the air.

I thought the trebuchets were fun and definitely worth doing. It is fun to watch how each group's trebuchet is going to do. All of them were extremely different and we all used different techniques to build them. The launching of the trebuchets went forward, backward, or didn't leave the sling. All were different and I liked seeing all of our reactions when each trebuchet was launched. I think building trebuchets should be done next year, but I think we should have a little more time. We had time to build them, but we were also working on our rockets while we needed to be thinking about building a trebuchet as well. All in all, I thought the trebuchets were fun and I loved seeing all of our reactions and excitement when we launched them!!

1 comment:

  1. nice bit of history
    good discussion of your project
    how much time do you need. three weeks was not enough?
    3

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