What of newtons laws appiled on a trebuchet?
The first of Newton's Laws describes the inertia that allows the projectile to leave the trebuchet. The second law describes the acceleration that the trebuchet applies to the projectile before it releases. The third law describes the reaction that occurs when the trebuchet is released, as the weight's force pushing down creates the reaction of launch.
Well he fundamentally proposed a few theories. But he is eminently known for introducing the 'Mathematical Principles of Natural Philosophy'. These principles include Newtons 3 laws of motion and his Gravitational Constant. If you want to know what they are, google, Newtons 3 laws. He was quite smart!