Des+&+Grovin-+Trebuchet

**__Trebuchet Project - Physics 30 Period 3__**
Purposes of a Trebuchet

-Trebuchets existed as far back as the Middle Ages as a siege weapon, the purpose of this machine was to destroy enemy barricades and walls. -Our purpose for our Trebuchet is to label the connection of Newton's Laws within the trebuchet that propels the object forward.

Application of Physics on a Trebuchet

-Projectile Motion: It is described that an object propelled through Newton's Laws which only has gravity acting upon it is called a Projectile. The range of motion throughout a Projectile, is called the trajectory. The trajectory appears as a parabolic curve due to us being relative to the Earth. In class, we discussed the optimum angle for a good trajectory. That angle would be 45°, as we also figured out that the Vx and Vy are equal at 45º.

-Centripetal Force: The force that dictates a body is pulled along the center of circular motion that helps the object accelerate without moving out of the circular position. EG: Our christmas ornament in our satchel that was used to launch the ball.

-Newton's 1st Law: This law states that, an object in motion stays in motion, and a object at rest stays in rest. This law is applied to our trebuchet because our firing is stationary due to the balanced force of the counterweight, and the hold of the firing pin.

-Newton's 2nd Law: Through unbalanced forces, an object accelerates: F=ma. The counterweight supplies the force alongside with gravity to propel the arm in a opposite direction that powers the other side of the arm to propel forwards, which in turn launches our christmas ornament out of the firing satchel.

Current Phase: Design Trebuchet

Initial draft: 100x100 centimetres

[[image:Treb_Measure_draft2.png width="459" height="459"]]
Projected Trebuchet Size

Projectile weight - 5 grams Counter weight - 1000 grams Range - 1500 cm

Drop of Counterweight- 15 cm Lower arm - 9 cm Upper arm - 70 cm Axle Height - 50 cm

Next Phase: Build test model

Materials Used: Electric Handsaw Pellets(For Counterweight) String (For Sling) Wood Glue Magnet (To hold the sling to the arm) Wooden Planks (20cmx3cm) x4 (Balsa) Screw (Firing Pin) Copper Tubing( To hold the arms) Tape Measure Metre Stick Weight Scale Screwdriver Drill

Procedure of building our Trebuchet 1. First we did the math using SOHCAHTOA to figure out how to cut the lengths of the wood to proper triangulated sides to hold up our trebuchet. 2. Then we decided to glue/screw our pieces of wood together to form the structure of our trebuchet. 3. A copper tube was decided upon to hold the sides of the trebuchet and the arm together. 4. The arm was made by attaching a 2 pieces of wood together, in a small "T" shape for one side to hold the firing satchel, and the counterweight. 5. A small platform was attached to our base of the trebuchet to hold the satchel in place, along with the arm with a firing pin. 6. Strings were attached using glue on the ends of the arm to hold onto the counterweight, and the satchel. 7. A piece of string was tied to the screw that was holding onto the firing pin, so we could spectate the trajectory from behind.

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Variations on our Trebuchet

-There was quite a couple of variations towards our first design of our Trebuchet. We first decided that we should drill a couple of holes within the arm that would allow the copper tubing to position the arm at different angles and launch the projectile. -We initially decided to add a lot of weight on our "counter-weight bucket", but then sooner found out that it would impact our P too much with the mass to produce an efficient number.


 * Trial || Mass (Kg) || Arm Length (m) || Dist. (m) || P = D/mL ||
 * 1 || 3 || 1.39 || 7 || 1.68 ||
 * 2 || 3 || 1.39 || 7 || 1.68 ||
 * 3 || 3.2 || 1.39 || 9.5 || 2.14 ||
 * 4 || 3.5 || 1.39 || 8.3 || 1.71 ||
 * 5 || 3.2 || 1.39 || 8.1 || 1.82 ||
 * 6 || 3.2 || 1.39 || 9 || 2.02 ||
 * 7 || 3.2 || 1.39 || 5 || 1.12 ||
 * 8 || 3.2 || 1.39 || 7.8 || 1.75 ||
 * 9 || 3.2 || 1.39 || 8 || 1.8 ||