Chapter 13: Liquids
Lecture OutlineChapter 13:Liquids 2015 Pearson Education, Inc.
This lecture will help you understand: PressurePressure in a LiquidBuoyancy in a LiquidArchimedes' PrincipleWhat Makes an Object Sink or FloatFlotationPascal's PrincipleSurface TensionCapillarity 2015 Pearson Education, Inc.
The force per unit area that one object exerts onanother In equation form:forcePressure area Depends on area over which force is distributed Units: N/m2, lb/ft2, or Pa (Pascals) 2015 Pearson Education, Inc.
Pressure Example: The teacher lying on nails is unharmed becauseforce is applied over many nails. Combinedsurface area of the nails results in a tolerable pressurethat does not puncture the skin. 2015 Pearson Education, Inc.
PressureCHECK YOUR NEIGHBORWhen you stand on one foot instead of two, theforce you exert on the floor isA.B.C.D.less.the same.more.None of the above. 2015 Pearson Education, Inc.
PressureCHECK YOUR ANSWERWhen you stand on one foot instead of two, theforce you exert on the floor isA.B.C.D.less.the same.more.None of the above.Comment:Distinguish between force and pressure! 2015 Pearson Education, Inc.
PressureCHECK YOUR NEIGHBORWhen you stand on one foot instead of two, thepressure you exert on the floor isA.B.C.D.less.the same.more.None of the above. 2015 Pearson Education, Inc.
PressureCHECK YOUR ANSWERWhen you stand on one foot instead of two, thepressure you exert on the floor isA.B.C.D.less.the same.more.None of the above.Explanation:Twice as much, in fact! 2015 Pearson Education, Inc.
Pressure in a Liquid Force per unit area that a liquid exerts on anobject Depth dependent and not volume dependent Example: Swim twice as deep, then twice asmuch weight of water above youproduces twice as much pressureon you. 2015 Pearson Education, Inc.
Pressure in a Liquid Acts equally in all directions Example:– Your ears feel the same amount of pressureunder water no matter how you tip your head.– Bottom of a boat is pushed upward by waterpressure.– Pressure acts upward when pushing a beachball under water. 2015 Pearson Education, Inc.
Pressure in a Liquid Independent of shape of container:– Whatever the shape of a container, pressureat any particular depth is the same. In equation form:Liquid pressure weight density x depth 2015 Pearson Education, Inc.
Pressure in a LiquidCHECK YOUR NEIGHBORWater pressure provided by a water tower isgreater if the towerA.B.C.D.is taller.holds more water.Both A and B.None of the above. 2015 Pearson Education, Inc.
Pressure in a LiquidCHECK YOUR ANSWERWater pressure provided by a water tower isgreater if the towerA.B.C.D.is taller.holds more water.Both A and B.None of the above.Explanation:Only depth, not amount of water, contributes to pressure. 2015 Pearson Education, Inc.
Pressure in a Liquid Effects of water pressure– Acts perpendicular tosurfaces of a container– Liquid spurts at rightangles from a hole in thesurface. The greater the depth, thegreater the exiting speed. 2015 Pearson Education, Inc.
Buoyancy in a Liquid Buoyancy– Apparent loss of weight of a submerged object– Amount equals the weight of water displaced 2015 Pearson Education, Inc.
Buoyancy in a Liquid Displacement rule:– A completely submerged object always displaces avolume of liquid equal to its own volume.– Example: Place a stone in a container that is brimfulof water, and the amount of wateroverflowequals the volume of the stone. 2015 Pearson Education, Inc.
Buoyancy in a LiquidCHECK YOUR NEIGHBORA cook who measures a specific amount of butterby placing it in a measuring cup with water in it isusing theA.B.C.D.principle of buoyancy.displacement rule.concept of density.All of the above. 2015 Pearson Education, Inc.
Buoyancy in a LiquidCHECK YOUR ANSWERA cook who measures a specific amount of butterby placing it in a measuring cup with water in it isusing theA.B.C.D.principle of buoyancy.displacement rule.concept of density.All of the above. 2015 Pearson Education, Inc.
Buoyancy in a Liquid Buoyant force– Net upward force that a fluid exertson an immersed object weight ofwater displaced– Example: The difference in theupward and downwardforces acting on thesubmerged block is thesame at any depth 2015 Pearson Education, Inc.
Buoyancy in a LiquidCHECK YOUR NEIGHBORHow many forces act on a submerged body at rest ina fluid?A.B.C.D.One—buoyancyTwo—buoyancy and the force due to gravityNone—in accord with the equilibrium rule, F 0None of the above. 2015 Pearson Education, Inc.
Buoyancy in a LiquidCHECK YOUR ANSWERHow many forces act on a submerged body at rest ina fluid?A.B.C.D.One—buoyancyTwo—buoyancy and the force due to gravityNone—in accord with the equilibrium rule, F 0None of the above. 2015 Pearson Education, Inc.
Buoyancy in a Liquid Sink or float?– Sink when weight of submerged object isgreater than the buoyant force.– Neither sink nor float when weight of asubmerged object is equal to buoyantforce—object will remain at any level.– Float when weight of submerged object isless than the buoyant force it would havewhen submerged—when floating, buoyantforce weight of floating object. 2015 Pearson Education, Inc.
Archimedes' Principle Archimedes' principle:– Discovered by Greek scientist Archimedes.– Relates buoyancy to displaced liquid.– States that an immersed body (completely orpartially) is buoyed up by a force equal to theweight of the fluid it displaces.– Applies to gases and liquids. 2015 Pearson Education, Inc.
Archimedes' Principle Apparent weight of a submerged object– Weight out of water — buoyant force Example: If a 3-kg block submerged in water apparently"weighs" 2 kg, then the buoyant force or weight of waterdisplaced is 1 kg. 2015 Pearson Education, Inc.
Archimedes' PrincipleCHECK YOUR NEIGHBOROn which of these blocks submerged in water is the buoyantforce greatest?A.B.C.D.1 kg of lead1 kg of aluminum1 kg of uraniumAll the same. 2015 Pearson Education, Inc.
Archimedes' PrincipleCHECK YOUR ANSWEROn which of these blocks submerged in water is the buoyantforce greatest?A.B.C.D.1 kg of lead1 kg of aluminum1 kg of uraniumAll the same.Explanation:The largest block is the aluminum one. It displaces morewater and therefore experiences the greatest buoyant force. 2015 Pearson Education, Inc.
Archimedes' PrincipleCHECK YOUR NEIGHBORWhen a fish expands its air bladder, the density of the fishA.B.C.D.decreases.increases.remains the same.None of the above. 2015 Pearson Education, Inc.
Archimedes' PrincipleCHECK YOUR ANSWERWhen a fish expands its air bladder, the density of the fishA.B.C.D.decreases.increases.remains the same.None of the above.Explanation:The largest block is the aluminum one. It displaces morewater and therefore experiences the greatest buoyant force. 2015 Pearson Education, Inc.
Archimedes' PrincipleCHECK YOUR NEIGHBORWhen a fish makes itself less dense, the buoyantforce on itA.B.C.D.decreases.increases.remains the same.None of the above. 2015 Pearson Education, Inc.
Archimedes' PrincipleCHECK YOUR ANSWERWhen a fish makes itself less dense, the buoyantforce on itA.B.C.D.decreases.increases.remains the same.None of the above. 2015 Pearson Education, Inc.
Archimedes' PrincipleCHECK YOUR NEIGHBORWhen a fish decreases the size of its air bladder,the density of the fishA.B.C.D.decreases.increases.remains the same.None of the above. 2015 Pearson Education, Inc.
Archimedes' PrincipleCHECK YOUR ANSWERWhen a fish decreases the size of its air bladder,the density of the fishA.B.C.D.decreases.increases.remains the same.None of the above. 2015 Pearson Education, Inc.
Archimedes' PrincipleCHECK YOUR NEIGHBORWhen a submarine takes water into its ballasttanks, its densityA.B.C.D.decreases.increases.remains the same.None of the above. 2015 Pearson Education, Inc.
Archimedes' PrincipleCHECK YOUR ANSWERWhen a submarine takes water into its ballasttanks, its densityA.B.C.D.decreases.increases.remains the same.None of the above. 2015 Pearson Education, Inc.
Archimedes' PrincipleCHECK YOUR NEIGHBORWhen a submerged submarine expels water fromits ballast tanks, its densityA.B.C.D.decreases.increases.remains the same.None of the above. 2015 Pearson Education, Inc.
Archimedes' PrincipleCHECK YOUR ANSWERWhen a submerged submarine expels water fromits ballast tanks, its densityA.B.C.D.decreases.increases.remains the same.None of the above.Explanation:This is how a submerged submarine is able to surface. 2015 Pearson Education, Inc.
Archimedes' Principle Flotation– Principle of flotation: A floating object displaces a weight of fluid equal to its ownweight. Example: A solid iron 1-ton block may displace 1/8 ton of waterand sink. The same 1 ton of iron in a bowl shape displaces agreater volume of water—the greater buoyant force allows it tofloat. 2015 Pearson Education, Inc.
Archimedes' PrincipleCHECK YOUR NEIGHBORThe reason a person finds it easier to float in saltwatercompared with freshwater is that in saltwaterA.B.C.D.the buoyant force is greater.a person feels less heavy.Neither of these.None of the above. 2015 Pearson Education, Inc.
Archimedes' PrincipleCHECK YOUR ANSWERThe reason a person finds it easier to float in saltwatercompared with freshwater is that in saltwaterA.B.C.D.the buoyant force is greater.a person feels less heavy.Neither of these.None of the above.Explanation:A floating person has the same buoyant force whatever the density ofwater. A person floats higher because a smaller volume of the densersaltwater is displaced. 2015 Pearson Education, Inc.
Archimedes' PrincipleCHECK YOUR NEIGHBOROn a boat ride, the skipper gives you a life preserver filledwith lead pellets. When he sees the skeptical look on yourface, he says that you'll experience a greater buoyant forceif you fall overboard than your friends who wearStyrofoam-filled preservers.A. He apparently doesn't know his physics.B. He is correct. 2015 Pearson Education, Inc.
Archimedes' PrincipleCHECK YOUR ANSWEROn a boat ride, the skipper gives you a life preserver filledwith lead pellets. When he sees the skeptical look on yourface, he says that you'll experience a greater buoyant forceif you fall overboard than your friends who wearStyrofoam-filled preservers.A. He apparently doesn't know his physics.B. He is correct.Explanation:He's correct, but what he doesn't tell you is you'll drown! Your lifepreserver will submerge and displace more water than those of yourfriends who float at the surface. Although the buoyant force on you willbe greater, the net force downward is greater still! 2015 Pearson Education, Inc.
FlotationCHECK YOUR NEIGHBORYou place an object in a container that isfull to the brim with water on a scale. Theobject floats, but some water spills out. How does the weight ofthe object compare with the weight of the water displaced?A.B.C.D.Weight of object is greater than weight of water displaced.Weight of object is less than weight of water displaced.Weight of object is equal to weight of water displaced.There is not enough information to decide. 2015 Pearson Education, Inc.
FlotationCHECK YOUR ANSWERYou place an object in a container that isfull to the brim with water on a scale. Theobject floats, but some water spills out. How does the weight ofthe object compare with the weight of the water displaced?A.B.C.D.Weight of object is greater than weight of water displaced.Weight of object is less than weight of water displaced.Weight of object is equal to weight of water displaced.There is not enough information to decide.Explanation:This principle is wonderfully illustrated with Scotland's Falkirk Wheel. 2015 Pearson Education, Inc.
The Falkirk Wheel's two caisson are brimful ofwater and the same weight, regardless of whetherthere are boats in them. This makes rotation andlifting almost effortless. 2015 Pearson Education, Inc.
Archimedes' Principle Denser fluids will exert a greater buoyant force ona body than less dense fluids of the same volume. Example: Ship will float higher in saltwater(density 1.03 g/cm3) than in freshwater(density 1.00 g/cm3). 2015 Pearson Education, Inc.
Archimedes' Principle Applies in air– The more air an object displaces,the greater the buoyant force on it.– If an object displaces its weight, ithovers at a constant altitude.– If an object displaces less air, itdescends. 2015 Pearson Education, Inc.
Archimedes' PrincipleCHECK YOUR NEIGHBORAs you sit in class, is there a buoyant force actingon you?A. No, as evidenced by an absence of liftB. Yes, due to displacement of air 2015 Pearson Education, Inc.
Archimedes' PrincipleCHECK YOUR ANSWERAs you sit in class, is there a buoyant force actingon you?A. No, as evidenced by an absence of liftB. Yes, due to displacement of airExplanation:There is a buoyant force on you due to airdisplacement, but much less than your weight. 2015 Pearson Education, Inc.
What Makes an Object Float or Sink? Whether an object floats or sinks dependsupon the– volume of the object.– volume of the fluid displaced. For an object to float:– Weight of object is less than buoyant forceof the liquid, i.e., less than the weight of theliquid it displaces. 2015 Pearson Education, Inc.
What Makes an Object Float or Sink? Three rules:1. An object more dense than the fluid in whichit is immersed will sink.2. An object less dense than the fluid in whichit is immersed will float.3. An object having a density equal to thedensity of the fluid in which it is immersedwill neither sink nor float. 2015 Pearson Education, Inc.
What Makes an Object Float or Sink?CHECK YOUR NEIGHBORTwo solid blocks of identical size are submerged in water.One block is lead and the other is aluminum. Upon which isthe buoyant force greater?A.B.C.D.On the lead blockOn the aluminum blockSame on both blocksThere is not enough information to decide. 2015 Pearson Education, Inc.
What Makes an Object Float or Sink?CHECK YOUR ANSWERTwo solid blocks of identical size are submerged in water.One block is lead and the other is aluminum. Upon which isthe buoyant force greater?A.B.C.D.On the lead blockOn the aluminum blockSame on both blocksThere is not enough information to decide.Explanation:The buoyant force depends upon the volume of the block that issubmerged. Since both submerged blocks are the same size, theydisplace the same volume of water. So they have the same buoyant force. 2015 Pearson Education, Inc.
Pascal's Principle Pascal's principle:– Discovered by Blaise Pascal, ascientist and theologian in the17th century– States that a change in pressureat any point in an enclosed fluidat rest istransmitted undiminished toall points in the fluid– Applies to all fluids—gasesand liquids 2015 Pearson Education, Inc.
Pascal's Principle Application in hydraulic press Example:– Pressure applied to the left piston is transmitted to the rightpiston.– A 10-kg load on small piston (left) lifts a load of 500 kg on largepiston (right). 2015 Pearson Education, Inc.
Pascal's Principle Application for gases and liquids:– Seen in everyday hydraulic devices used in construction– In auto lifts in service stations Increased air pressure produced by an air compressor istransmitted through the air to the surface of oil in anunderground reservoir. The oil transmits the pressure to thepiston, which lifts the auto. 2015 Pearson Education, Inc.
Pascal's PrincipleCHECK YOUR NEIGHBORIn a hydraulic device, it is impossiblefor theA. output piston to move farther thanthe input piston.B. force output to exceed the forceinput.C. output piston's speed to exceedthe input piston's speed.D. energy output to exceed energyinput. 2015 Pearson Education, Inc.
Pascal's PrincipleCHECK YOUR ANSWERIn a hydraulic device, it is impossiblefor theA. output piston to move farther thanthe input piston.B. force output to exceed the forceinput.C. output piston's speed to exceedthe input piston's speed.D. energy output to exceed energyinput. 2015 Pearson Education, Inc.
Surface Tension The contractive tendency of thesurface of liquids is due tosurface tension. Examples:– When you submerge a wirein water and pull it out with aspring, the spring stretches.– When you place apaintbrush in water and pullit out, the water contractsand pulls the hairs together. 2015 Pearson Education, Inc.
Surface Tension Other examples:– Drops of any kind arespherical because theirsurfaces tend to contractand force each drop intothe shape having the leastsurface area for a givenvolume – a sphere.– Bubbles are spherical forthe same reason – surfacetension. 2015 Pearson Education, Inc.
Surface Tension Surface tension is caused bymolecular attractions. Beneath the surface, each moleculeis attracted in every direction by neighboring molecules. A molecule on the surface of a liquid is pulled only byneighbors on each side and downward from below; thereis no pull upward. These molecular attractions tend to pull the moleculefrom the surface into the liquid, causing surface tension. 2015 Pearson Education, Inc.
Surface Tension Factors affecting surface tension:– The type of liquid Water has greater surface tension than oil.– What is mixed with the liquid Soapy water has lower surface tension than waterwithout soap.– Temperature of the liquid The molecules in a hot liquid have higher energyand are not bound tightly as in a cooler liquid. 2015 Pearson Education, Inc.
Capillarity The rise of a liquid in a fine,hollow tube or in a narrow spaceis called capillarity.– Adhesion between the moleculesof the glass and water draws thefilm of water into the tube.– Surface tension causes the film onthe surface to contract.– This raises the liquid from below torise into the tube.– When the force of the surfacetension balances out the weight ofthe liquid, the liquid stops rising. 2015 Pearson Education, Inc.
Capillarity The height of rise dependsupon the weight of the liquidand the narrowness of thetube.– The lighter the liquid, thehigher the capillary rise.– The narrower the tube, thehigher the capillary rise 2015 Pearson Education, Inc.
Capillarity Examples:– Oil rises in a wick.– Hair let loose in a bathtub causes the scalp toget wet.– Insects have a hard time getting out of waterwhen their legs get wet. 2015 Pearson Education, Inc.
Archimedes' Principle Flotation – Principle of flotation: A floating object displaces a weight of fluid equal to its own weight. Example: A solid iron 1-ton block may displace 1/8 ton of water and sink. The same 1 ton of iron in a bowl shape displaces a grea
Part One: Heir of Ash Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6 Chapter 7 Chapter 8 Chapter 9 Chapter 10 Chapter 11 Chapter 12 Chapter 13 Chapter 14 Chapter 15 Chapter 16 Chapter 17 Chapter 18 Chapter 19 Chapter 20 Chapter 21 Chapter 22 Chapter 23 Chapter 24 Chapter 25 Chapter 26 Chapter 27 Chapter 28 Chapter 29 Chapter 30 .
TO KILL A MOCKINGBIRD. Contents Dedication Epigraph Part One Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6 Chapter 7 Chapter 8 Chapter 9 Chapter 10 Chapter 11 Part Two Chapter 12 Chapter 13 Chapter 14 Chapter 15 Chapter 16 Chapter 17 Chapter 18. Chapter 19 Chapter 20 Chapter 21 Chapter 22 Chapter 23 Chapter 24 Chapter 25 Chapter 26
DEDICATION PART ONE Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6 Chapter 7 Chapter 8 Chapter 9 Chapter 10 Chapter 11 PART TWO Chapter 12 Chapter 13 Chapter 14 Chapter 15 Chapter 16 Chapter 17 Chapter 18 Chapter 19 Chapter 20 Chapter 21 Chapter 22 Chapter 23 .
2.1 Flammable liquids Flammable liquids are liquids that will ignite easily and burn rapidly. More precisely, they are liquids with flash points that do not exceed 100 F (37.8 C). Less flammable liquids with flash points at 100 F or higher are categorized as combustible liquids. For storage purposes, flamma
13.2 The Nature of Liquids I. A Model for Liquids A. Liquids are Fluids 1. Substances that can flow and therefore take the shape of their container B. Liquids have Relatively High Density 1. 10% less dense than solids (average) a. Water is an exception 2. 1000x more dense than gases C. Liquids are Relatively Incompressible 1.
a) Mixing of liquids and soluble solids b) Mixing of liquids and insoluble solids 1. (a) Mixing of two miscible liquids (homogeneous mixtures e.g. solutions) – mixing of two miscible liquids is quite easy and occur by diffusion. Such type of mixing does not create any problem. Simple shaking or stirring is enough but if the liquids are not .
About the husband’s secret. Dedication Epigraph Pandora Monday Chapter One Chapter Two Chapter Three Chapter Four Chapter Five Tuesday Chapter Six Chapter Seven. Chapter Eight Chapter Nine Chapter Ten Chapter Eleven Chapter Twelve Chapter Thirteen Chapter Fourteen Chapter Fifteen Chapter Sixteen Chapter Seventeen Chapter Eighteen
18.4 35 18.5 35 I Solutions to Applying the Concepts Questions II Answers to End-of-chapter Conceptual Questions Chapter 1 37 Chapter 2 38 Chapter 3 39 Chapter 4 40 Chapter 5 43 Chapter 6 45 Chapter 7 46 Chapter 8 47 Chapter 9 50 Chapter 10 52 Chapter 11 55 Chapter 12 56 Chapter 13 57 Chapter 14 61 Chapter 15 62 Chapter 16 63 Chapter 17 65 .
