3.
Segment V1.3: Capillary Tube Viscometer
(Related to Textbook Section 1.6 - Viscosity)
Most devices (called viscometers) used to determine viscosity do not measure it directly, but instead measure some characteristic with a known relationship to viscosity.
The capillary tube viscometer involves the laminar flow of a fixed volume of fluid through a capillary tube. The time required for the fluid to pass through the tube is a measure of the kinematic viscosity of the fluid. As shown with the four tubes, the drain times can vary depending on the viscosity of the fluid and the diameter of the capillary tube.
4.
Segment V1.4: Non-Newtonian Behavior
(Related to Textbook Section 1.6 - Viscosity)
Fluids for which shearing stress is not linearly related to the rate of shearing strain are designated as non-Newtonian fluids.
A mixture of water and corn starch, when placed on a flat surface, flows as a thick, viscous fluid. However, when the mixture is rapidly disturbed, it appears to fracture and behave more like a solid. The mixture is a non-Newtonian shear thickening fluid which becomes more viscous as the shearing rate is suddenly increased through the rapid action of the spoon.
5.
Segment V1.5: Floating Razor Blade
(Related to Textbook Section 1.9 - Surface Tension)
Surface tension forces exist at liquid/gas or liquid/solid interfaces. Although these forces are relatively small, they are quite important in many situations.
A heavier-than-water, double-edged steel razor blade can float on water. Without surface tension, the blade would sink because its weight is greater than its buoyant force. However, surface tension forces are not large enough to support a slightly heavier singleedged blade.