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 …..