Jack's Science Fair Project

							Science Fair Project
       Projectile Projection
                 Trebuchets
                Jack Tiffany
Statement of the Problem

  Does the weight of the counterweight and/or projectile
        affect the distance the projectile is launched?
             Project Overview

I shot the projectiles while changing the weight
          of the projectile and that of the
   counterweight. I then recorded all of it on a
                       chart.
                     Research
    Summarize your research here in three to five bullet points:
     Trebuchets have been used since the middle ages.
       Trebuchets are more accurate than catapults.
          Trebuchets are more simple to make.
      The Trebuchet was invented in China in 300AD
                              Variables

     Independent variable: The weight of the counterweight and the projectile.
          Dependent variable: The distance the projectile is launched.
   Constant variables: Length of the arm, size of trebuchet, distance arm is pulled,
                       amount of time launched, size of basket.
               Control group: The 10 launches with my 1lb weight
                         Hypothesis
     Hypothesis/Prediction is the more the weight of the counterweight the
    farther the projectile will go. The heavier the projectile the less far it will
                                         go.
                     Materials
   Trebuchet from Science Olympiads
   20g, 40g, and 60g ball from Science Olympiads
   3 meter sticks
   A 1lb, a 2lb, a 3lb counterweight
                            Procedure

   1. set the counterweight to 1lb
   2. Load the 40g ball into the basket
   3. Pull back string to mark 5.
   4. Launch, measure, and record.
   5. Repeat steps 2-4 9 more times
   6. Set the counterweight to 2lbs.
   7. Repeat steps 2-4 10 times.
   8. Set the counterweight to 3lbs
   9. Repeat steps 2-4 10 times
   10. Record all the results on the chart
                   Data/Observations (Analyzes)

1 kg at 40 grams                            2kg at 40 gramms        rams               3 kg at 40 grams




trails                   distance           trails                  distance           trails                  distance




                     1               1.24                       1               1.42                       1               1.62
                     2               1.29                       2               1.34                       2               1.72




                     3               1.27                       3                1.3                       3                1.8




                     4               1.28                       4                1.4                       4               1.61




                     5               1.46                       5               1.45                       5               1.63




                     6               1.29                       6                1.4                       6                1.6




                     7               1.26                       7               1.38                       7               1.64




                     8               1.34                       8                1.4                       8                1.7




                     9               1.23                       9               1.27                       9                1.8




                    10                 1                       10               1.43                      10                1.5




                                    1.266                                      1.379                                      1.662
                       Conclusion
 The heavier the counterweight, the farther the projectile is launched.
The heavier the projectile is, the less distance the projectile is launched.
     Possible Experimental Errors
 I may have launched it at mark 4 a few times.
 The string may have caught on the arm, reducing the distance.
 I may have not accurately measured the ball a few times.
    Applications and Recommendations


     To improve the results, I would have run the experiment 15 times instead of 10. Also I
    would have made sure to check the recoil. This could be used in real life if you were trying
    to throw a basket ball and a bowling ball. You wanted to throw them to a friend and didn’t
                                   know how much force to use.