First of all I want to mention, that I've found many questions around this site and in other websites dealing with my question; however, I don't think they answer my question fully. So I am here to re-ask it and specify some things so that whoever will answer it can focus on my ideas and help me understand momentum better.
So here is my question: Why is momentum conserved in inelastic collisions (perfectly inelastic or just inelastic)?
So here is what I thought about in this question: I understand that elastic collisions have the K.E conserved but inelastic don't.
So in inelastic if K.E is not conserved then... Wnet=deltaKE (work energy theorm) so here that means that their is work done and a net force acting on the system.
Now from impulse momentum... Ft=deltap (isnt here F not equal zero so the change in momentum not equal zero?)
So basically my confusion comes in the fact that to have a change in momentum their must be a force and time, and the force exists because K.E changes?
I hope you will help me understand this concept more, because I cant seem to wrap my head around it. What am I doing wrong?