It is well known that a fluid opposes the motion of a moving object and we can represent this resistance in motion with a force, which we call it drag.
Different fluids exert different drag forces which must be attributed to the different strength of the intermolecular interactions of each fluid.
Mechanism
When an object (e.g. a sphere) moves inside a fluid (e.g. water) it "breaks" the intermolecular bonds between the molecules of the fluid. Breaking the bonds increases the potential energy of the fluid. This energy increase must be come from somewhere and so the kinetic energy of the moving object must decrease.
Is the above mechanism correct? What I want to understand is what happens at the microscopic level that gives rise to the force we call drag.
