Grade 8 Science Unit 3: Fluids & Viscosity

GRADE 8 SCIENCEUNIT 3: FLUIDS &VISCOSITYChapter 7: Viscositydescribes a fluid’sresistance to flow

PTM... A REVIEW PG. 270All matter is made up ofvery tiny particles.All particles in a puresubstance are the samebut different from anothersubstance.

CAN YOU IDENTIFY THE 3STATES OF MATTER?

3 STATES OF MATTER... AREVIEWState Shape Volume ParticlearrangementParticlemovement1. Solid Definite Definite Close Vibrate2. Liquid Indefinite Definite Close Freeflowing3. Gas Indefinite indefinite Far Apart Random

FLUIDSAny form of matter thatflows.Since liquids and gasesdo NOT have a definiteshape they are able toflow making themfluids.

WE USE FLUIDS EVERYDAY.FOR EXAMPLE...Food fluids (water, oil, maplesyrup, honey, etc)Cleaning fluids and creamsBodily fluidsIndustrial fluids (compressedair in tires, lubricants, etc)

VISCOSITYA measure of a liquid’sresistance to flow.The thickness orthinness of a fluid.A fluid that is viscous isthe one that is NOT“runny” (flows slowly).

VISCOSITY & FRICTION?Friction resistsmovement.The greater the friction,the greater the viscosity.The particles areholding on tightly toeach other.

VISCOSITY IS IMPORTANT INOUR EVERYDAY LIFE.

FLOW RATEThe speed at which afluid flows from one pointto another.Slow Medium FastCorn syrupDishwashingliquidWater

Core Lab Activity7-2 B pg. 282-3THE FLOW RATE OF LIQUIDS

FACTORS THAT AFFECTVISCOSITYTemperature:As you increase temperature,you decrease a fluid’sviscosity. As you decreasetemperature, you increase afluid’s viscosity.The opposite is true of gases.

Concentration:The amount of asubstance dissolved in aspecific volume.Increasing theconcentration, increasesthe viscosity.

Attractive Forces:If the attractive forcesare strong, it is difficultfor the particles to pullaway thereby the fluidflows slowly and is moreviscous.

Particle size:The smaller the particlesize, the faster the fluidflows and is less viscous.