In this Unreal Engine 5.3 Niagara tutorial, we dive into Mass Mode! Learn how particle mass affects behavior, how to link mass with particle size or rotational inertia, and when to use physical material presets (like wood, steel, or paper) in your VFX simulations. 
https://dev.epicgames.com/community/learning/tutorials/xdKVO/unreal-engine-ue5-3-niagara-basic-mass-mode-18