Understanding Fluid Behavior and Viscosity

What is Newton's law of viscosity?

• Newton's law of viscosity describes the relationship between shear stress and shear rate in a fluid.

• It defines the density of a fluid in relation to its temperature.

• It states that all fluids have the same viscosity regardless of temperature.

• It explains the gravitational force acting on a fluid in motion.

Define viscosity in the context of fluid mechanics.

• Viscosity is the measure of a fluid's resistance to flow and deformation.

• Viscosity is the temperature at which a fluid boils.

• Viscosity is the speed at which a fluid flows under pressure.

• Viscosity is the density of a fluid at rest.

What are the units of viscosity?

• Newton-second (N·s)

• Joule (J)

• Cubic meter per second (m³/s)

• Pascal-second (Pa·s) or poise (P) in CGS system.

Explain the difference between Newtonian and non-Newtonian fluids.

• Both types of fluids have the same flow behavior but differ in temperature sensitivity.

• Newtonian fluids have constant viscosity and linear flow behavior, while non-Newtonian fluids have variable viscosity and non-linear flow behavior.

• Non-Newtonian fluids have constant viscosity and linear flow behavior.

• Newtonian fluids have variable viscosity and linear flow behavior.

Give an example of a Newtonian fluid.

• Olive oil

• Honey

• Air

• Water

What is shear stress in relation to viscosity?

• Viscosity is the force per unit area applied to a fluid.

• Shear stress is the same as viscosity.

• Shear stress is the force per unit area that causes fluid flow, and viscosity measures the fluid's resistance to this shear stress.

• Shear stress only occurs in solid materials.

Describe how temperature affects the viscosity of a fluid.

• Temperature has no effect on viscosity.

• As temperature decreases, viscosity increases.

• Higher temperatures always increase viscosity.

• Temperature inversely affects viscosity; as temperature increases, viscosity decreases.

What is the significance of the Reynolds number in fluid dynamics?

• It indicates the density of a fluid.

• It determines the viscosity of a fluid.

• The Reynolds number is significant in fluid dynamics as it helps predict flow behavior, distinguishing between laminar and turbulent flow.

• It measures the temperature of a fluid.

List two applications of fluids with high viscosity.

• Water in construction applications

• Glycerin in cosmetic products

• Lubricants in automotive applications, honey in food applications.

• Air in pneumatic systems

What is a Bingham plastic?

• A Bingham plastic is a liquid that flows freely without any resistance.

• A Bingham plastic is a solid that cannot be deformed under any circumstances.

• A Bingham plastic is a type of gas that expands under pressure.

• A Bingham plastic is a material that behaves as a solid until a yield stress is applied, then flows like a viscous fluid.