I am studying about fluids at the moment and I never been so massively confused since about some fluid related topics that I thought I was confident about like liquid pressure, velocity of particles, buoyancy. The more I research the more I realize that I don't think I understand what is the cause/source of liquid pressure, manner of liquid particle movement anymore. And after much time spent scouring the web, I realize the main source of this problem, which is that I have been visualizing liquid molecules like an ideal gas particle this whole time, which I realize now is not correct.
I obviously knew from basic physics chapters that liquid molecules are closer to each other (in terms of distance) than gas particle, but somehow I still visualized liquid molecules as constantly zipping off and colliding with each other and sides of container in full velocity like gas particles. I saw liquid particles are moving everywhere freely without much hindrance, from one extreme side of container to another, from bottom of container to top of liquid level just like how gas particles freely bounces from top of container to bottom of container like a ball . With this assumption, I then thought of fluid pressure as property arising from collision among particles and between particles and container, without significant influence from gravity (since gravity does not play much role in gas pressure, from what i know. I could be wrong though! Please correct me if this is also not correct) But I now realize that something is wrong in these assumptions because I am at loss to understand topics like fluid pressure, buoyancy, velocity
My main question then is that how is liquid particles organized around each other in a container? How do they move around each other? Are they free to move anywhere without much hindrance? Why does gravity play a significant role in liquid pressure but not ideal gas pressure? When i submerge a object in liquid, why don't the object simple sink in the bottom of container no matter how light or heavy it is, because individual liquid molecules are free to move right? So why don't they simple keep on moving to side, up, down and obviously raise liquid level while making space for the object? Why go through whole explanation of buoyancy force, floating, half submerged, full submerged head ache? If anyone can please explain this issue or point me to any direction, I would greatly appreciate it. Thanks.