I worked on more collision problems, these were more about things hitting each other and not falling things. There was also this question of a cat jumping back and forth two moving sleds and it was challenging for me because it uses a lot of relative velocity stuff and the number of collisions. there was a gravity assist problem which is really easy if you know the elastic collision assumption. and then theres this problem on a ball hitting two target balls at the same time. This was actually on the 2025 f=ma questions 2-3 which I did not solve. I unfortunately did not solve this even though ive seen it like 3 months ago. But it was cause I only tried to use momentum and I really had to use both momentum and energy so Im not sure why energy straight up did not come to my mind. maybe it was all the problems I did before were more momentum and impulse based and I just forgot energy existed. then theres this really hard problem asking to prove something about the deflection angle. Theres this solution by feynman lectures that i think is really genius in how it uses the center mass frame, i havent fully understood it yet so ill still be learning it