Viscosity
Isaac Newton studied viscosity
Viscosity: Connecting with Chemistry and Biology
Does air resistance increase as v or v2???
Air resistance produced by collisions of gas molecules
Air Resistance Increases with Temp
Proportional to v for slow speeds
Proportional to v2 for higher speedsBecause of turbulence
Reynolds number provides dividing line
Visc.smd
Viscosity/friction in a fluid
Decreases with increasing Temp
Produced by decreasing intermolecular forces
Non-Newtonian Fluids
Viscosity_liquid.smd
3 oils/5 temp
Dr. Jean Leonard Marie Poiseuille Checks his heart
Applications
Bernoulli’s equation
Non-newtonian fluids
Pouiselle’s Equation: Q ~ r4
Alt. Models:fractals,percolation
Introduction
Provides a connection between math, chemistry Biology and
Physics
Provides students a chance to look at alternate scientific models.
Provides a molecular explanation as an alternate to the usual
continuous model
Intended Audience
AP,Honors, Regular Physics
Builds on what students have learned in other classes
Adjustments/Adaptations
None required-all levels of Physics can handle
Placement in Curriculum
After kinematics and dynamics
Some concepts such as Pressure were learned in Chem
Goals and Objectives
Determine the relationship between temp and viscosity for both gases
and liquids
Compare different models for viscosity
Understand the usefulness of Reynold’s number
As a criterion for distinguishing turbulent and nonturbulent flow.
Give reports on the application of viscosity to other fields such as
Biology, Chemistry and Engineering
Day 1: Air Resistance(Wet Lab)
Coffee Filter Lab
•F v or F v2 ????•Cedar Point/Six Flags•Cold Air+Warm Air
Day 2: Macro Micro(Computer)
Visc.smd
•F v (Stokes)
•F=P/t * A versus m,T
Time Line
Day 3: Kinetic Karnival Video:
“Viscosity”
Lab:Marbles in Oil(Wet)
Non-NewtonianFluids (Corn Starch,Slime etc).
versus T for liquid
Day 4: liquid.smd(Computer)
Demo: KMn04 in warm H2O(wet)
H increases with temp in gas(collisions increase)but decreases in liquid( intermolecular forces)
Day 5 Bernoulli’s Equation
Continuity Equation
Endless numbers of examples
From groundhogs, to baseballs to airplane wings
Day 6 Poiseulle’s Equation /Heart Q ~ r4
Relate the velocity profile of a fluid in a pipe to Poiseulle’s Equation
Day 7 bernoulli_xtal.smd Airfoil crystal
Using SMD students build a crystal in the shape of an airfoil
Day 8: Student Reports 5 minute seminar
Examples from other sciences/enginering
The End
….. Thank You …..