What is the difference between "kinematics" and "dynamics"?
In classical mechanics "kinematics" generally refers to the study of properties of motion-- position, velocity, acceleration, etc.-- without any consideration of why those quantities have the values they do. "Dynamics" means a study of the rules governing the interactions of these particles, which allow you to determine why the quantities have the values they do.
Thus, for example, problems involving motion with constant acceleration ("A car starts from rest and accelerates at 4m/s/s. How long does it take to cover 100m?") are classified as kinematics, while problems involving forces ("A 100g mass is attached to a spring with a spring constant of 10 N/m and hangs vertically from a support. How much does the spring stretch?") are classified as "dynamics."
That's kind of an operational definition, at least.
- Statics: Study of forces in equilibrium without consideration of changes over time.
- Kinematics: Study of motions (position, velocity, acceleration) and all possible configurations of a system subject to constraints.
- Kineto-statics: Study of forces in equilibrium, with the addition of motion related forces (like inertia forces via D'Alembert's principe) one instant at the time. Results from one time frame do not affect the results on the next time frame.
- Dynamics: Full consideration of time varying phenomena in the interaction between motions, forces and material properties. Typically there is an time-integration process where results from one time frame effect the results on the next time frame.
As far as the source if kinematic and dynamic viscocity, I am not sure, and I have wondered this myself. Maybe it stems from the test methods used to measure each property.
Since everybody already gave nice replies to this question, I'll give a more pragmatic answer:
Don't worry about it. It is an arbitrary distinction made by humans. Nature doesn't care if some phenomenon can be described/explained purely from kinematic considerations or not. It's not a fundamental distinction.
On the other hand, it is a useful distinction. I'm sure you know the distinction somehow implicitly when you solve problems.
Let me give an example in mechanics: you swing a pendulum in a vertical plane, you swing sufficiently fast so that the trajectory is a circle. What is the tension in the pendulum when it passes in the lowest point of the circle. The tension is a dynamical quantity, because it is a force. Now, when you solve the problem, you don't write down the full equation of Newton and solve them. You use the kinematic information you have about the trajectory: it's a circle, in the lowest part of the trajectory there is no tangential acceleration, so the acceleration is directed radially inwards and is $v^2/r$. From this you can find the tension by using purely kinematic considerations and never solving $\vec{F}=m\vec{a}$ as a differential equation.
I guess you understood that in physics we do this all the time. If we didn't, many problems would be impossible to tackle without resorting to extensive computer simulations all the time. In most problems we consider, we already have some idea of the kinematics, which permits to reduce the space of acceptable solutions. Sometimes so drastically (but that is only for the simplest problems) that we can solve them by purely kinematic considerations.