The human Organism and the behaviour of fluids

Copy the black, just read the red.

WHAT DO YOU KNOW ABOUT FLUIDS?

Follow along in your workbook pg. 37 Both classes should have this completed Universal kids need to get notes from someone else or complete using textbook

Fluids fluid = a substance that can flow and take shape of its container All liquids and gases = fluids The body is full of fluids- gas and liquid

Compressible Fluid = volume can change Gas= compressible fluid because its particles are far apart air tanks for scuba divers, propane tanks for the BBQ

Incompressible fluid- volume cannot be varied Liquids = incompressible fluid because its particles are close together Gives a transmission of force from one particle to another inside the substance (like dominos) Hydraulic brakes The blood forced through vessels by the pumping heart

syringes

Remember? S- space A- attraction M- movement E- energy

Particles and Fluids gas S- lots A- no bonds M- zip quickly E - high

Particles and Fluids liquid S- close M- slide past E - medium A- weak bonds M- slide past E - medium

Fluids or Not? Gels & pastes = fluids only if they flow and take on the shape of their containers Powders –sugar, sand = not fluids even though they have no form and flow They do not naturally assume the shape of the container *

The Bottle Diver Activity Rinse out a 2 L pop bottle and then fill it to the top. Place an eye dropper into the water and fill ¼ full with water (just to let it sit at the surface of the water in the bottle.) Cap the bottle tightly. Compress the bottle and see what happens to the eye dropper. Done with both classes

Why does the Bottle Diver dive? Can you make the diver stay in one place in the bottle? What is happening at this point? If you pour out half of the water in the bottle, it becomes much harder to sink the diver.  Why? How Does It Work? The Cartesian diver, named after French philosopher and scientist René Descartes, works because of several factors. When you squeeze the sides of the bottle, you are increasing the pressure on the liquid inside. That increase in pressure is transmitted to every part of the liquid. That means you are also increasing pressure on the eye dropper itself. Squeeze hard enough and you will push some more water up inside the dropper. The air inside the dropper squeezes tighter as more water is forced in. Increasing The Density Now, water is much denser than air. So when you push more water inside the dropper, you increase its overall density. Once its density is greater than that of its surroundings, it will sink. Release the pressure on the bottle’s sides and you stop forcing water inside the eye- dropper. The air inside it will now push out the extra water again, and the eye-dropper will rise. That’s the Cartesian Diver!

Homework Workbook pg. 38 Assigned to group 33 and 34 and checked

Textbook Pg. 85, 1-4 Done by both classes (should be handed in Wednesday at latest) – get it back next week

Pressure

Pressure (P) Pressure =result of force applied perpendicularly to a surface unit of measure = pascals (Pa)

The Force -an action that changes the movement of an object e.g. Stop, move, slow

When apply force on a fluid = fluid exerts a force on whatever contains it (bottle divers)

Fill in workbook pg. 39 Done by both classes

Force and Pressure Variation in force Result Force incr. P incr. Force Decr. P decr. Increased mass = greater force = greater pressure

Surface Area and Pressure Variation in S.A Result S.A. P Increased surface area (S.A.) = force distributed = less pressure

Pressure Math P= pressure in Pascals- Pa F= force in Neutons - N A= surface area in square metres –m2 Just be able to explain it

If a person stands on a nail, the foot will be punctured However, if the person lays down on a bed of nails the skin would not be broken. Why? What is the similarity with snowshoes? *

Did You Know? There is more pressure per square centimetre exerted under the heel of a stiletto shoe than under the Empire State Building?

Homework: Workbook pg. 40-42 skip 3, 4 &6 Assigned when we reach this slide – due November 26 (Wednesday)

Discussion: Textbook pg. 85 questions 6 & 8 Not done by either class yet

Bill Nye Fluids Not finished by either class

Pressure exerted by fluids

Follow in workbook pg. 43 Done with both classes

P & Incompressible fluids (liquids) 1. mass of fluid above the object. More fluid above = greater force = greater pressure As swim deeper = feel it in ears total quantity of fluid not important Like being on the bottom of a human pile up of 5 people vs. 50 people on top

Linking this real life Water towers are raised to use gravity and the mass of the water to increase the pressure of the water leaving the tower.

Higher density = greater force = greater pressure 2. density of liquid Higher density = greater force = greater pressure Consider the human pile up with 10 skinny people on top vs. 10 Sumo wrestlers

Glaucoma Optic nerve damage in the eye caused by increased pressure inside the eye

P & Compressible Fluids (gases) When particles of compressible fluids collide = exert a force on the obstacle. collisions = P

as volume increases Pressure decreases As volume decreases Pressure increases as pressure increases Volume decreases As pressure decreases volume increases

Factors affecting Number of Collisions particles = more collide = P temperature = E to particles = move more and collide more = P volume = same number of particles in less space = collide more = P If students ran around room at full speed = would bump into each other or the walls. Now double # of students = more bumps Give students more E (2 energy drinks and a bag of candy) = run faster = more bumps Take class size and bring desks back in around the edges (less space to run) = more bumps

Ear and Pressure As ascend a mountain = external pressure decreases & eardrum swells can affect hearing, and can hurt air enters the Eustachian tubes (between ears and throat), the pressure is equalized may notice a POP as this happens and the discomfort will stop.

Discussion: Textbook pg. 86 questions 10-16 Not done with either class

Announcements Fluids Test (Chapter 3) Group 34  Thursday, December 4th Fluid Projects due today! Make a pile on my desk – If you need to email it to me my email is tara.irwin@mail.mcgill.ca Discussion Questions due today Group 33 – Wednesday December 3rd

Principles of Pressure (RULES) Fluid ALWAYS moves from high pressure to low pressure Paintball CO2 canister is opened and liquid expands out into a gas from the tank of high pressure, into a space of lower pressure. When pressure is equal inside and outside of tank, tank is “empty” and will not propel any more

Pressure applied to the surface of a fluid inside a closed container = uniformly distributed to every part of the fluid Using a syringe to inject medication into a patient

A transfer of pressure in a fluid can increase the force involved.

Natural Mechanisms Your heart is a pump that regulates the pressures of the blood in the body Blood pressure in arteries ranges from 120 mm Hg when the heart contracts and pushes the blood out to 75 mm Hg when the heart is at rest

When you breathe your diaphragm contracts and lowers into your abdomen When you breathe your diaphragm contracts and lowers into your abdomen. This creates a larger volume inside the chest and a lower pressure in your lungs than outside. As air flows from high P to low P, air rushes in. The reverse happens when you exhale.

Homework Workbook pg. 44-45, skip 6 Not done by either class yet

Discussion: Textbook pg. 87 questions 17-21 Not done by either class yet

Build a Concept Map Read page 112 in your Toolbox on how to create a Concept Map Using the ALL the words on page 87 to create a concept map for Chapter 3 of your textbook. You can use your notes too. Not done by either class yet

Study questions workbook pg. 46-48 skip 3 & 8 Not done by either class yet