In the middle ages, in spite of all the nonsense in the romantic novels, most warfare revolved around sieges. Offense and defense evolved in parallel. The castles got thicker walls; and to knock them down the trebuchet was invented. There is a lot of material on the net about trebuchets.
So I got tired of working on my picture frames and built a model of a trebuchet out of scrap wood.
Lots of variables here. Quite a complicated simple-looking device. Medieval trebuchets could throw 100 Kg a distance of 100 meters -- at least, the modern reproductions can do this. One monster I saw on YouTube (made out of steel) can actually fling a compact car!
Spring is here and I have the garden to do; I think trebuchet tuning will have to wait.