I have no idea about "Chapter 3: Equilibrium of a Particle" and "Chapter 4: Force System Resultants". Honestly, I am terrible at physics and Vector stuff.

Link of Chapter 3 lecture note: https://drive.google.com/file/d/1WC-t62XQdC9dtijPM4Su3ikshUx7Kn9P/view?usp=sharing

Link of Chapter 4 Part 1 lecture note: https://drive.google.com/file/d/1R3O_DgVuoya1NoTecz9qdcDLyUPHb122/view?usp=sharing

Link of Chapter 4 Part 2 lecture note: https://drive.google.com/file/d/1T0dIl3hp9kri9YMp7Ds3IRgNqCZqGJog/view?usp=sharing

So, could you send me the video link(s) and/or YouTube channel(s) that explain "Chapter 3: Equilibrium of a Particle" and "Chapter 4: Force System Resultants" in detail?