An ideal fluid flows through a vertically oriented cylindrical tube of varying radius with cross-section shown. Point C is higher than point B, and B is higher than A. What can we conclude about the fluid pressure at points A, B, and C? PB PC PA Pc PB > PA PA PB PC PB > PA > PC A More information is needed to determine at least one of these relationships. B C

In an immersion measurement of a woman's density, she is found to have a mass of 62.0 kg in air and an apparent mass of 0.0850 kg when completely submerged with lungs empty. (a) What mass of water does she displace? (b) What is her volume? (c) Calculate her density. (d) If her lung capacity is 1.75 L is she able to float without treading water with her lungs filled with air?

Considering the magnitude of typical arterial blood pressures, why are mercury rather than water manometers used for these measurements?

(a) Suppose a blood vessel's radius is decreased to 90.0% of its original value by plaque deposits and the body compensates by increasing the pressure difference along the vessel to keep the flow rate constant. By what factor must the pressure difference increase? (b) If turbulence is created by the obstruction, what additional effect would it have on the flow rate?

An ideal fluid flows through a horizontal pipe whose diameter varies along its length. Measurements would indicate that the sum of the kinetic energy per unit volume and pressure at different sections of the pipe would (a) decrease as the pipe diameter increases, (b) increase as the pipe diameter increases, (c) increase as the pipe diameter decreases, (d) decrease as the pipe diameter decreases, or (e) remain the same as the pipe diameter changes.

(a) Using Bernoulli's equation, show that the measured fluid speed v for a pitot tube, like the one in Figure 12.7(b), is given by v=( 2gh)1/2 , where h is the height of the manometer fluid, is the density of the manometer fluid, is the density of the moving fluid, and g is the acceleration due to gravity. (Note that v is indeed proportional to the square root of h, as stated in the text.) (b) Calculate v for moving air if a mercury manometer's h is 0.200 m. Figure 12.7 Measurement of fluid speed based on Bernoulli's principle. (a) A manometer is connected to two that are close together and small enough not to disturb the flow. Tube 1 is open at the end facing the flow. A dead spot having zero speed is created there. Tube 2 has an opening on the side, and so the fluid has a speed V across the opening; thus, pressure there drops. The difference in pressure at the manometer is 12v22 , and so h is proportional to 12v22 . (b) This type of velocity measuring device is a Prandtl tube, also known as a pitot tube.

What is the difference between flow rate and fluid velocity? How are they related?

(a) Using Bernoulli's equation, show that be measured fluid speed v for a pitot tube, like the one in figure 14.32(b), is given by v=( 2gh)1/h , where h is be height of be manometer fluid, p' is the density of the manometer fluid, p is the density of the moving fluid, and g is be acceleration due to gravity. (Note that v is indeed proportional to the square root of h, as stated in text) (b) Calculate v for moving air if a mercury manometer's h is 0.200 m. Figure 14.32 Measurement of fluid speed on Bernoulli’s principle. (a) A manometer is connected to two tubes close together and small enough not to disturb the flow. Tube 1 is open at the end facing the flow. A dead spot having zero speed is created there. Tube 2 has an opening on the side, so the fluid has a speed v across; thus, pressure there drops. The difference in pressure at the manometer is 12v22 , so h is proportional to . 12v22 (b) This type of velocity measuring device is a Prandtl tube, also known as a pitot tube.

A manometer is shown in Figure P15.36. Rank the pressures at the five locations indicated from highest to lowest. Indicate equal pressures, if any. FIGURE P15.36

(a) What is the density of a woman who floats in freshwater with 4.00% of her volume above the surface? This could be measured by placing her in a tank with marks on the side to measure how much water she displaces when floating and when held under water (briefly). (b) What percent of her volume is above the surface when she floats in seawater?