Lachlan – my first question is what is a trebuchet?
Simple answer …It’s a type of catapult.
Here is an image of a very early trebuchet
Here is an image that may help your understanding and give you some clues on how the trebuchet works. When the mass 1 is released it begins to accelerate towards the ground. In doing so a force is applied to the beam pulling it down. That force is then applied, via the beam to the mass 2. What do you think will happen to Mass 2?
The support for the beam, the fulcrum, is in a particular position. Any thoughts on that? You could create a see-saw and investigate the application of forces when the fulcrum changes position ……altering d1 and d2.