4.5. Newtonian and Non-Newtonian Fluids

Try these first

1. 1.

   What is a Newtonian fluid?

   Hint

   Look for examples of fluids in daily life.

2. 2.

   Define viscosity.

   Hint

   Think about how thick or runny a substance is.

3. 3.

   What is viscosity?

   • A measure of a fluid's temperature
   • A measure of a fluid's resistance to flow
   • A measure of a fluid's density

   Hint

   Consider how liquids like water and syrup behave.

4. 4.

   True or False: Non-Newtonian fluids exhibit constant viscosity.

   • True
   • False

   Hint

   Think about how substances like slime behave under different conditions.

5. 5.

   A cylindrical container is filled with a Bingham plastic fluid. Calculate the force required to initiate flow if the yield stress is given as 5 Pa and the cross-sectional area of the container is 0.1 m².

   Hint

   Start by using the yield stress definition.

6. 6.

   If the viscosity of a liquid decreases by 10% when the temperature is increased from 20°C to 40°C, calculate the new viscosity if the original viscosity was 0.01 Pa.s.

   Hint

   Calculate 10% of the initial viscosity first.