What is the physics behind a trebuchet counterweight?

Lauren: What is the physics behind a trebuchet counterweight?
ok….me and my friend have a physics report to do over trebuchets. Our teacher wants us to right an intro that takes up a half a page. We have explained some of the history and how the trebuchet workd but we have to put some bull crap about the physics behind it like formulas and stuff. We are doing the report over the counterweight and how it effects the object being launched we just need help on figuring out the physics behind the counterweight…plz help we are really stuck on this.

Answers and Views:

Answer by da person
as you have figured out the counter weight drop very quickly when the throwing arm is released.
The gravity effects the counter weight. The more weight the quicker the drop though the counter weight has to be enough to counter act the projectile weight.

the arm lengths also effect things.
you might want to check this out

it all comes down to a delicate balance between weights and how much gravity effects this.

Answer by The Legendary Masked Akitist
Mechanical energy is used to raise the counterweight, and is stored there as gravitational potential energy until the treb is triggered. At that point it transfers some of that energy through the arm, which is a Class 1 lever, to the missile, through the action of the sling. The rest of the energy is dissipated as friction, either in the post-launch oscillations of the arm and counterweight or in temporarily distorting the structural parts of the treb.