Girls Bulid a Trebuchet

I am a junior in high school and in my physics class we were told to either bulid a trebuchet or catapolt.
We are a group of girls who were able to bulid a trebuchet that went 29.3 meters. 
 

 In this step we used two 2X4's to make the height of the base arm (cream color) 48 inches long. (one for each side). We drilled the arms on the inside middle of the base.

We also drilled a hole about 38 inches from the top in the center for our rebarr. (next step) 

 The rebar and the throwing arm are added in this step.
We used a 2X4 that was 48 inches long.
To make the hole go through on both sides a drill was used. 
Make sure that the rebar or whatever you use goes all the way across and come out on both sides of the base arm.

 The purple is the support for the throwing arm
We made the hole too big; this is to help stabalize it.
We also added plastic ties on both sides of the throwing arm.
The purple is 2X4's about 8 inches long for each side.

 In this step we added wheels to the bottom.
We found that in research that it is supposed to make the distance further.
Theses are your basic cart wheels form a hard ware store.

 Bucket was added.
We used a laundary deturgent bucket. 
The bigger you have the bucket the more objects to put in for a further distance.
To make the bucket stay we used a large i-hook that we screwed into the top of the throwing arm. 

 For this we screwed a nail into the bottom potion of the throwing arm and put electrical tape around it.
Next we got rope that is as long as the throwing arm and folded it in half. Cut in the middle of this .
we made our pouch out of mesh.
Tie the rope on both sides of the mesh.
Now get a key chain ring and tie the rope onto that.

 To launch this. you must wrap the end of the rope with out the ring on to the screw with the electrical tape on it. Make sure both sides are equal length. place the ring on the end and pull down on the arm so that that bucket is up top. Use force. Act like Friction. Add as much weight as you thing the bucket can handle. When getting ready to let go, the pouch has to be stretched and in the middle of the base 2X4's. Let go.

This represents Newton's second law: What goes up must come back down.

The speed is almost 300 meters per second.

The velocity is almost 300 meters per second towards the JV softball field.

 When we were walking out to go and launch the rocks created inertia so we couldn't push it any more until we moved them.

For weight we used, large rocks.