Reflection on Test day #3

Part 3

To calculate the theoretical range you use the following formula: 2*h* (M/m)
H- stands for the heights that the bucket falls in meters
M- the weight you use (counterweight)
m- the weight of the tennis ball

2*(0.98 m)*(22.6796 kg/ 0.0624 kg) = 712.37 meters
After we got all of our weights and measurements we came up with a theoretical range of 712.
37 meters for our trebuchet. This is obviously a drastic comparison to our average distance that we were shooting of 23.44 meters. There are multiple reasons why I think our trebuchet didn't perform as well as it could've. On our launch day we defintely had murphy there with us! The biggest reason in my mind why it maybe didn't shoot as far would be the angle of release. The nail seemed to be loose and kept wiggling on us, therefore when we went to hammer it in it got slightly changed which can make a big difference. Our arm was another big problem for us. The arm randomly broke off for us after our 3rd throw which meant that in order for us to have an arm we had to shorten it which affected the distance. It was much easier having a fixed weight in the sense that you weren't constantly changing things, but it did make it a bit harder to shoot farther since we couldnt add any weight. I think if we would've added even 25 pounds we wouldve got an extra 10 meters out of it. We saw this in our mini model with the washers, that the more weight you have the farther it seems to go. Another thing that worked in our favour sometimes and other times not was the pouch. I think that if we would've spent more time on that part of the project we wouldn't have had the problem of the ball staying in the pouch or rolling out. Lastly, an even longer length for our pouch strings would've been beneficial, because gravity would've had more time to play its' role of force on it.

Ready to let the trigger system release

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Part 4 

On the day of our trebuchet challenge we began with a 10 minute time frame where we were able to set everything up and make any minor adjustments. After the 10 minutes was up we got 20 minutes to launch 5 times to try and achieve an average of 25 for full marks. Our launches were marked at the following distances:

Launch 1- 20.2 meters

Launch 2- 25.8 meters

Launch 3- 43.6 meters

Launch 4- 0.00 meters

Launch 5- 27.6 meters

After we completed the launches this gave us an average of 23.44 meters. We were happy with all of the distances that our trebuchet shot, other than the 0 meters. The ball not shooting at all made it that much harder for us to try and get a 25 meter average. Overall I was pleased with how it ended up working for us.

The things that we had planned, and did change for the accuracy part of our trebuchet was the arm length, sling length and the angle of release. We shortened both the length of the arm and sling so that there was less time for gravity to effect the ball. The change of the angle of release was almost 60 degrees rather than 45 so that it would shoot higher up rather than farther across. In the end most of our adjustments paid off.

Trebuchet