1. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu To View the presentation as a slideshow with effects select “View” on the menu bar and click on “Slide Show.” To advance through the presentation, click the right-arrow key or the space bar. From the resources slide, click on any resource to see a presentation for that resource. From the Chapter menu screen click on any lesson to go directly to that lesson’s presentation. You may exit the slide show at any time by pressing the Esc key. How to Use This Presentation

2. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter Presentation Transparencies Sample Problems Visual Concepts Standardized Test Prep Resources

3. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Fluid Mechanics Chapter 8 Table of Contents Section 1 Fluids and Buoyant Force Section 2 Fluid Pressure Section 3 Fluids in Motion

4. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Fluids and Buoyant Force Chapter 8 Objectives Define a fluid. Distinguish a gas from a liquid. Determine the magnitude of the buoyant force exerted on a floating object or a submerged object. Explain why some objects float and some objects sink.

5. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Fluids and Buoyant Force Chapter 8 Defining a Fluid A fluid is a nonsolid state of matter in which the atoms or molecules are free to move past each other, as in a gas or a liquid. Both liquids and gases are considered fluids because they can flow and change shape. Liquids have a definite volume; gases do not.

6. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Fluids and Buoyant Force Chapter 8 Density and Buoyant Force The concentration of matter of an object is called the mass density. Mass density is measured as the mass per unit volume of a substance.

7. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 8 Mass Density Section 1 Fluids and Buoyant Force

8. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Fluids and Buoyant Force Chapter 8 Density and Buoyant Force, continued The buoyant force is the upward force exerted by a liquid on an object immersed in or floating on the liquid. Buoyant forces can keep objects afloat.

9. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 8 Buoyant Force and Archimedes’ Principle Section 1 Fluids and Buoyant Force

10. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 8 Displaced Volume of a Fluid Section 1 Fluids and Buoyant Force

11. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Fluids and Buoyant Force Chapter 8 Density and Buoyant Force, continued Archimedes’ principle describes the magnitude of a buoyant force. Archimedes’ principle: Any object completely or partially submerged in a fluid experiences an upward buoyant force equal in magnitude to the weight of the fluid displaced by the object. F B = F g (displaced fluid) = m f g magnitude of buoyant force = weight of fluid displaced

12. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 8 Buoyant Force on Floating Objects Section 1 Fluids and Buoyant Force

13. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 8 Buoyant Force Section 1 Fluids and Buoyant Force

14. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Fluids and Buoyant Force Chapter 8 Density and Buoyant Force, continued For a floating object, the buoyant force equals the object’s weight. The apparent weight of a submerged object depends on the density of the object. For an object with density  O submerged in a fluid of density  f, the buoyant force F B obeys the following ratio:

15. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Fluids and Buoyant Force Chapter 8 Sample Problem Buoyant Force A bargain hunter purchases a “gold” crown at a flea market. After she gets home, she hangs the crown from a scale and finds its weight to be 7.84 N. She then weighs the crown while it is immersed in water, and the scale reads 6.86 N. Is the crown made of pure gold? Explain.

16. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Fluids and Buoyant Force Chapter 8 Sample Problem, continued Buoyant Force 1. Define Given: F g = 7.84 N apparent weight = 6.86 N  f = p water = 1.00  10 3 kg/m 3 Unknown:  O = ?

17. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Fluids and Buoyant Force Chapter 8 Diagram: Sample Problem, continued Buoyant Force 1. Define, continued TIP: The use of a diagram can help clarify a problem and the variables involved. In this diagram, F T,1 equals the actual weight of the crown, and F T,2 is the apparent weight of the crown when immersed in water.

18. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Fluids and Buoyant Force Chapter 8 Sample Problem, continued Buoyant Force 2. Plan Choose an equation or situation: Because the object is completely submerged, consider the ratio of the weight to the buoyant force.

19. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Fluids and Buoyant Force Chapter 8 Sample Problem, continued Buoyant Force 2. Plan, continued Rearrange the equation to isolate the unknown:

20. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Fluids and Buoyant Force Chapter 8 Sample Problem, continued Buoyant Force 3. Calculate Substitute the values into the equation and solve:

21. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Fluids and Buoyant Force Chapter 8 Sample Problem, continued Buoyant Force 4. Evaluate From the table, the density of gold is 19.3  10 3 kg/m 3. Because 8.0  10 3 kg/m 3 < 19.3  10 3 kg/m 3, the crown cannot be pure gold.

22. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Fluid Pressure Chapter 8 Objectives Calculate the pressure exerted by a fluid. Calculate how pressure varies with depth in a fluid.

23. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Fluid Pressure Chapter 8 Pressure Pressure is the magnitude of the force on a surface per unit area. Pascal’s principle states that pressure applied to a fluid in a closed container is transmitted equally to every point of the fluid and to the walls of the container.

24. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 8 Pascal’s Principle Section 2 Fluid Pressure

25. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Fluid Pressure Chapter 8 Pressure, continued Pressure varies with depth in a fluid. The pressure in a fluid increases with depth.

26. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 8 Fluid Pressure as a Function of Depth Section 2 Fluid Pressure

27. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Fluids in Motion Chapter 8 Objectives Examine the motion of a fluid using the continuity equation. Recognize the effects of Bernoulli’s principle on fluid motion.

28. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Fluids in Motion Chapter 8 Fluid Flow Moving fluids can exhibit laminar (smooth) flow or turbulent (irregular) flow. An ideal fluid is a fluid that has no internal friction or viscosity and is incompressible. The ideal fluid model simplifies fluid-flow analysis.

29. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 8 Characteristics of an Ideal Fluid Section 3 Fluids in Motion

30. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Fluids in Motion Chapter 8 Principles of Fluid Flow The continuity equation results from conserva- tion of mass. Continuity equation A 1 v 1 = A 2 v 2 Area  speed in region 1 = area  speed in region 2

31. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Fluids in Motion Chapter 8 Principles of Fluid Flow, continued The speed of fluid flow depends on cross- sectional area. Bernoulli’s principle states that the pressure in a fluid decreases as the fluid’s velocity increases.

32. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 8 Bernoulli’s Principle Section 3 Fluids in Motion

33. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice 1. Which of the following is the correct equation for the net force acting on a submerged object? A. F net = 0 B. F net = (  object –  fluid )gV object C. F net = (  fluid –  object )gV object D. F net = (  fluid +  object )gV object Standardized Test Prep Chapter 8

34. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice 1. Which of the following is the correct equation for the net force acting on a submerged object? A. F net = 0 B. F net = (  object –  fluid )gV object C. F net = (  fluid –  object )gV object D. F net = (  fluid +  object )gV object Standardized Test Prep Chapter 8

35. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 2. How many times greater than the lifting force must the force applied to a hydraulic lift be if the ratio of the area where pressure is applied to the lifted area is 1/7 ? F. 1/49 G. 1/7 H. 7 J. 49 Standardized Test Prep Chapter 8

36. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 2. How many times greater than the lifting force must the force applied to a hydraulic lift be if the ratio of the area where pressure is applied to the lifted area is 1/7 ? F. 1/49 G. 1/7 H. 7 J. 49 Standardized Test Prep Chapter 8

37. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 3. A typical silo on a farm has many bands wrapped around its perimeter, as shown in the figure below. Why is the spacing between successive bands smaller toward the bottom? A. to provide support for the silo’s sides above them B. to resist the increasing pressure that the grains exert with increasing depth C. to resist the increasing pressure that the atmosphere exerts with increasing depth D. to make access to smaller quantities of grain near the ground possible Standardized Test Prep Chapter 8

38. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 3. A typical silo on a farm has many bands wrapped around its perimeter, as shown in the figure below. Why is the spacing between successive bands smaller toward the bottom? A. to provide support for the silo’s sides above them B. to resist the increasing pressure that the grains exert with increasing depth C. to resist the increasing pressure that the atmosphere exerts with increasing depth D. to make access to smaller quantities of grain near the ground possible Standardized Test Prep Chapter 8

39. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 4. A fish rests on the bottom of a bucket of water while the bucket is being weighed. When the fish begins to swim around in the bucket, how does the reading on the scale change? F. The motion of the fish causes the scale reading to increase. G. The motion of the fish causes the scale reading to decrease. H. The buoyant force on the fish is exerted downward on the bucket, causing the scale reading to increase. J. The mass of the system, and so the scale reading, will remain unchanged. Standardized Test Prep Chapter 8

40. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 4. A fish rests on the bottom of a bucket of water while the bucket is being weighed. When the fish begins to swim around in the bucket, how does the reading on the scale change? F. The motion of the fish causes the scale reading to increase. G. The motion of the fish causes the scale reading to decrease. H. The buoyant force on the fish is exerted downward on the bucket, causing the scale reading to increase. J. The mass of the system, and so the scale reading, will remain unchanged. Standardized Test Prep Chapter 8

41. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued Use the passage below to answer questions 5–6. A metal block (  = 7900 kg/m 3 ) is connected to a spring scale by a string 5 cm in length. The block’s weight in air is recorded. A second reading is recorded when the block is placed in a tank of fluid and the surface of the fluid is 3 cm below the scale. Standardized Test Prep Chapter 8 5. If the fluid is oil (  < 1000 kg/m 3 ), which of the following must be true? A. The first scale reading is larger than the second reading. B. The second scale reading is larger than the first reading. C. The two scale readings are identical. D. The second scale reading is zero.

42. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued Standardized Test Prep Chapter 8 5. If the fluid is oil (  < 1000 kg/m 3 ), which of the following must be true? A. The first scale reading is larger than the second reading. B. The second scale reading is larger than the first reading. C. The two scale readings are identical. D. The second scale reading is zero. Use the passage below to answer questions 5–6. A metal block (  = 7900 kg/m 3 ) is connected to a spring scale by a string 5 cm in length. The block’s weight in air is recorded. A second reading is recorded when the block is placed in a tank of fluid and the surface of the fluid is 3 cm below the scale.

43. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued Standardized Test Prep Chapter 8 6. If the fluid is mercury (  = 13 600 kg/m 3 ), which of the following must be true? F. The first scale reading is larger than the second reading. G. The second scale reading is larger than the first reading. H. The two scale readings are identical. J. The second scale reading is zero. Use the passage below to answer questions 5–6. A metal block (  = 7900 kg/m 3 ) is connected to a spring scale by a string 5 cm in length. The block’s weight in air is recorded. A second reading is recorded when the block is placed in a tank of fluid and the surface of the fluid is 3 cm below the scale.

44. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued Standardized Test Prep Chapter 8 6. If the fluid is mercury (  = 13 600 kg/m 3 ), which of the following must be true? F. The first scale reading is larger than the second reading. G. The second scale reading is larger than the first reading. H. The two scale readings are identical. J. The second scale reading is zero. Use the passage below to answer questions 5–6. A metal block (  = 7900 kg/m 3 ) is connected to a spring scale by a string 5 cm in length. The block’s weight in air is recorded. A second reading is recorded when the block is placed in a tank of fluid and the surface of the fluid is 3 cm below the scale.

45. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued Use the passage below to answer questions 7–8. Water near the top of a dam flows down a spillway to the base of the dam. Atmospheric pressure is identical at the top and bottom of the dam. Standardized Test Prep Chapter 8 7. If the speed of the water at the top of the spillway is nearly 0 m/s, which of the following equations correctly describes the speed of the water at the bottom of the spillway?

46. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued Use the passage below to answer questions 7–8. Water near the top of a dam flows down a spillway to the base of the dam. Atmospheric pressure is identical at the top and bottom of the dam. Standardized Test Prep Chapter 8 7. If the speed of the water at the top of the spillway is nearly 0 m/s, which of the following equations correctly describes the speed of the water at the bottom of the spillway?

47. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued Use the passage below to answer questions 7–8. Water near the top of a dam flows down a spillway to the base of the dam. Atmospheric pressure is identical at the top and bottom of the dam. Standardized Test Prep Chapter 8 8. If the cross-sectional area of the spillway were half as large, how many times faster would the water flow out of the spillway? F. 1/4 G. 1/2 H. 2 J. 4

48. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued Use the passage below to answer questions 7–8. Water near the top of a dam flows down a spillway to the base of the dam. Atmospheric pressure is identical at the top and bottom of the dam. Standardized Test Prep Chapter 8 8. If the cross-sectional area of the spillway were half as large, how many times faster would the water flow out of the spillway? F. 1/4 G. 1/2 H. 2 J. 4

49. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Short Response 9. Will an ice cube float higher in water or in mercury? Explain your answer. Standardized Test Prep Chapter 8

50. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Short Response, continued 9. Will an ice cube float higher in water or in mercury? Explain your answer. Answer: mercury; because the density of mercury is greater than that of water Standardized Test Prep Chapter 8

51. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Short Response, continued 10. The approximate inside diameter of the aorta is 1.6 cm, and that of a capillary is 1.0  10 –6 m. The average flow speed is about 1.0 m/s in the aorta and 1.0 cm/s in the capillaries. If all the blood in the aorta eventually flows through the capillaries, estimate the number of capillaries. Standardized Test Prep Chapter 8

52. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Short Response, continued 10. The approximate inside diameter of the aorta is 1.6 cm, and that of a capillary is 1.0  10 –6 m. The average flow speed is about 1.0 m/s in the aorta and 1.0 cm/s in the capillaries. If all the blood in the aorta eventually flows through the capillaries, estimate the number of capillaries. Answer: 2.5  10 10 capillaries Standardized Test Prep Chapter 8

53. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Short Response, continued 11. A hydraulic brake system is shown below. The area of the piston in the master cylinder is 6.40 cm 2, and the area of the piston in the brake cylinder is 1.75 cm 2. The coefficient of friction between the brake shoe and wheel drum is 0.50. What is the frictional force between the brake shoe and wheel drum when a force of 44 N is exerted on the pedal? Standardized Test Prep Chapter 8

54. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Short Response, continued 11. A hydraulic brake system is shown below. The area of the piston in the master cylinder is 6.40 cm 2, and the area of the piston in the brake cylinder is 1.75 cm 2. The coefficient of friction between the brake shoe and wheel drum is 0.50. What is the frictional force between the brake shoe and wheel drum when a force of 44 N is exerted on the pedal? Answer: 6.0 N Standardized Test Prep Chapter 8

55. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Extended Response Standardized Test Prep Chapter 8 Base your answers to questions 12–14 on the information below. Oil, which has a density of 930.0 kg/m 3, floats on water. A rectangular block of wood with a height, h, of 4.00 cm and a density of 960.0 kg/m 3 floats partly in the water, and the rest floats under the oil layer. 12. What is the balanced force equation for this situation?

56. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Extended Response Standardized Test Prep Chapter 8 Base your answers to questions 12–14 on the information below. Oil, which has a density of 930.0 kg/m 3, floats on water. A rectangular block of wood with a height, h, of 4.00 cm and a density of 960.0 kg/m 3 floats partly in the water, and the rest floats under the oil layer. 12. What is the balanced force equation for this situation? Answer: F B,oil + F B,water = F g,block

57. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Extended Response, continued Standardized Test Prep Chapter 8 Base your answers to questions 12–14 on the information below. Oil, which has a density of 930.0 kg/m 3, floats on water. A rectangular block of wood with a height, h, of 4.00 cm and a density of 960.0 kg/m 3 floats partly in the water, and the rest floats under the oil layer. 13. What is the equation that describes y, the thickness of the part of the block that is submerged in water?

58. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Extended Response, continued 13. What is the equation that describes y, the thickness of the part of the block that is submerged in water? Answer: Standardized Test Prep Chapter 8 Base your answers to questions 12–14 on the information below. Oil, which has a density of 930.0 kg/m 3, floats on water. A rectangular block of wood with a height, h, of 4.00 cm and a density of 960.0 kg/m 3 floats partly in the water, and the rest floats under the oil layer.

59. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Extended Response, continued Standardized Test Prep Chapter 8 Base your answers to questions 12–14 on the information below. Oil, which has a density of 930.0 kg/m 3, floats on water. A rectangular block of wood with a height, h, of 4.00 cm and a density of 960.0 kg/m 3 floats partly in the water, and the rest floats under the oil layer. 14. What is the value for y?

60. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Extended Response, continued 14. What is the value for y? Answer: 1.71  10 –2 m Standardized Test Prep Chapter 8 Base your answers to questions 12–14 on the information below. Oil, which has a density of 930.0 kg/m 3, floats on water. A rectangular block of wood with a height, h, of 4.00 cm and a density of 960.0 kg/m 3 floats partly in the water, and the rest floats under the oil layer.

61. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Fluids in Motion Chapter 8 Principles of Fluid Flow

62. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Fluids in Motion Chapter 8 Principles of Fluid Flow