fluids

fluid

• loose bonding between molecules of liquid or gas

what is considered as fluids?

• gas and liquid

Liquids vs gas

fluid mechanics

• science with the response of fluids to the forces exerted upon them

• branch of classical physics with the applications in many branches of sciecne

properties of fluids

• viscosity

• density

• SG

• pressure

density

• P = m/v

• mass per unit volume of a fluid

• highly dependent on pressure and temperature

jhas the lowest density

• gases

encompasses a range of densityies

• liquids

how density affects an object in fluid

• less dense than fluid = floats

• more dense than fluid = sinks

• same density = remains suspended

• ultimately determines whether an objects, floats, sinks, or remains suspended

why oil floats on top of water

• chemical nature and polarity is different between the two

• water is polar, oil is nonpolar

• oil is less dense than water

how a lava lamp works

1. oil starts at the bottom bcs it is denser than water

2. heat warms the oil, causing its density to decrease

   1. this is because heat = excited molecules = pushing oil to be bigger in volume, thus less dense

3. less dense oil than water makes it rise

4. oil cools at the top = increases its density and sinks

5. cycle repeats

specific gravity

• ratio of a fluid’s density to the density of water at 4 DEGREES CELSIUS

• provides a unitless comparison to evaluate purity or concentraiton

• basically js compares how dense an object is to water at 4 degrees celsius

practical uses of SG

• clinical diagnosis, wine making

wine making

• dissolved sugar = increases liquid’s SG

• yeast converts sugar into ethanol, which drops SG values signal fermentation progress

pressure

• force exerted per unit of area

viscosity

resistance of a fluid to flow or deformation

• dictates how easily fluid moves thru pipes, valves, veins, etc.

archimedes principle

• upward buoyant force that is exerted on a body immersed in fluid

buoyancy

• ability of a fluid to support an object placed in it

buoyant force

• upward force exerted by the fluid on the object

• always acts upwards

displaced fluid

• fluid pushed aside by the object

direction

• buoyant force always acts upwards

how archimedes principle strengthens concept of buoyant force

• weight of fluid displaced is directly proportional to the buoyant force

• upward push of the water is the same weight as ghe water that got pushed out of the way