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# Science behind trebuchet

Klaw 2
For my last year in my school I have to make a final project about something that relates to one (or more) of my classes.

Anyway i am doing it about trebuchets.
if you don't know what it is, klick here

I am doing this for my Physics class, and I have to for one find by using my own calculations etc. (not googling it in and handing that over). I have to find out a few things like what the "best configuration" is and how much of the original energy of the gravity is transferred to the projectile etc.etc.

I gotta start next week with it, when school starts. So here is the question, has anyone some information I can use? Sites etc.
I would be thankfull for any information.
Magicman
The trick of a trebuchet is to keep the counterweight in a straight downward motion as long as possible. You want to transfer as much of the potential energy in the counterweight as possible into kinetic energy in the projectile.
jwellsy
I would design 3 of them.
Each based on the same same pattern.
But sized to different scales.

The goal of each one would be to "Kick/throw" a football field goal.
The smallest one would kick a 25 yard feild goal.
The others would be from 50 and 100 yards away.

Your calcs would show not only the machine description but the flight of the footballs.
See if you can visually prove the concept of 'Economy of Scale'.
Would doubling the work output require a machine smaller than twice the size?

The shop class would get a big kick out of helping to build them.
Other teachers and community people would love to help too.
You would just have to do the initial basic calc outlines, then delegate/orchestrate the rest of it.

Then you could put on an exhibition at a pep rally or a game halftime show.

You would be certain of an 'A'.
Deuxansenchine
Wow this is a nice project!! I always loved to throw things.

My first rock thrower was a kind of big slingshot. Between two trees and four medical elastics and a leather pocket to hold the rock in the middle. The rock was potato sized and me and my friend together were able to throw the rock 75 meters away. The game ended when when one of the elastic broke and slapped painfully my arm.

The second one was the very cool potato thrower covered with fiber glass. We used it with tennis ball and could reach 100m!

I guest a trebuchet would be sooo cool to design!! Keep us informed about your project!!
Tumbleweed
I recently went to Warwick Castle (In the UK) there they have a nice example of a trebuchet

I volunteered to be a human hampster in one of the large wheels , but they would'nt let me
DoctorBeaver
 Magicman wrote: The trick of a trebuchet is to keep the counterweight in a straight downward motion as long as possible. You want to transfer as much of the potential energy in the counterweight as possible into kinetic energy in the projectile.

For this reason it is best to put it on wheels. A solid base will cause the counterweight to fall in an arc. By adding wheels, the base will move to allow the weight to drop vertically.