Hi, first post on the forum! We know that kinetic energy is not conserved in an inelastic collision, and how much of the kinetic energy is lost we can find it out through applying conservation of momentum. But one thing that I don't understand is how does the system know exactly how much kinetic energy to lose? I understand that the kinetic energy is lost to heat, the internal energy of the objects that collided etc. But I find it strange that the before and after collision kinetic energy is not the same, and 'magically' a chunk of kinetic energy has been taken out from the system without accounting for where the kinetic energy goes directly. It's like A and B with mass M_a and M_b collide, then there must be a total kinetic energy E_1 lost in this system. How the energy is distributed to internal potential energy, heat, sound etc does not matter as long as it adds up to E_1. Isn't that peculiar? Shouldn't it be that how the energy is lost to internal potential energy, heat etc be different from system to system? I hope you understand what I'm asking here.