Question #2ca98

1 Answer
Mar 6, 2017

The answer is more dependent on the electrical character of molecules constituting a medium.


Suppose let us assume that there is a medium which has some fluid filled over (be it air or liquid). Assume another body (fluid or solid) moving through it.
We know that electrical forces are radially outward in nature. So, when a body moves in any direction in space, it always carries with itself deviation from minimization principle for least action. So, it carries with it that tendency to pull back.

However when that body is in relative motion it experiences less pull because there is simply not enough time during the brief contact during motion to settle down both the bodies (or their surfaces in contact). Also since the medium is an extended body and any disturbance created has to permeate to the "other end", it takes time which isn't allowed. How much exactly depends on the type of material.
Hence we have the amount of force (opposing) force experienced depending upon two factors viz., Relative velocity between medium and particle, and the amount of time the medium takes to permeate the given force.

Time factor is entirely dependent on the type of medium (coefficient of viscosity and the likes of it ) hence we have a variable force that changes with velocity instead of position like all other forces.
For bodies that are not that fast, viscous force can really be neglected. When apply this fluid in fluid movement there will be turbulence. This is the reason why we see less turbulence with less speed or high viscosity.