A fluid is a substance which can flow, so some examples of fluids would be coffee, tap water, and steam.
the frictional force occurs timewise based on the container and the viscosity of the liquid itself. Its actual mass can be calculused about the container as if one block was to move another block,...
Circulating blood is a non-newtonian fluid
no im pretty sure a molecule is a solid if that's what you mean...
Extracellular