Fluid Mechanics (CLB 11003) Chapter 3: Static fluid TUTORIAL 3 1. Define Pascal’s law. 2. What is difference between gage pressure and absolute pressure? 3. A vacuum gage connected to a chamber reads 24 kPa at a location where the barometric reading is 600 mm Hg. Determine the absolute pressure in the chamber (Hg = 13,590 kg/m3). (Ans: 56 kPa) 4. The water in a tank is pressurized by air and the pressure is measured by a multifluid manometer as shown in Figure 1. Determine the gage pressure of air in the tank is if h1 = 0.2 m, h2 = 0.3 m and h3 = 0.46 m. Take the densities of water, oil and mercuries to be 1000 kg/m3, 850 kg/m3 and 13,600 kg/m3, respectively. (Ans:56.9 kPa) Figure 1 5. Determine the pressure exerted on the surface of a submarine cruising 300 ft below the free surface of the sea. Assume that the barometric pressure is 14.7 psia and the specific gravity of sea water is 1.03 (water at 32F is 62.4 lbm/ft3). (Ans: 149 psia) 56). Show that the pressure at point A can be expressed as: PA = mangh2 – Pgh1 Fluid P Density.43 m. man Figure 3 8. The pressure at the bottom of a tank of water is measured with a mercury manometer where hwater = 3. What is the gauge pressure at the bottom of the tank? (Relative density mercury = 13. D A h2 h1 B C Manometric Fluid Density. (Ans: 27.8 kPa) Figure 4 .Fluid Mechanics (CLB 11003) Chapter 3: Static fluid 6. What are the values of P(x). PA(y) and PB(z) as shown in Figure 2? P = PA PA = 90 kPa gauge Local atmospheric pressure PA = (y) kPa abs abs PB = (z) kPa g P = (x) kPa g = 101 kPa abs P = PB Patm = 101 kPa abs PB = 51 kPa abs Absolute Zero P = 0 Pa abs Figure 2 7.0m and hmercury = 0. 600 kg/m3. what is the pressure difference measured by the manometer? (Ans: 75. Fresh and seawater flowing in parallel horizontal pipelines are connected to each other by a double U-tube manometer as shown in Figure 6.34 kPa) Figure 5 10.39 kPa) P1 P2 Figure 6 .Fluid Mechanics (CLB 11003) Chapter 3: Static fluid 9. A U-tube manometer containing mercury of density 13600 kg/m3 is used to measure the pressure drop along a horizontal pipe.6m. water and mercury to be sea = 1035 kg/m3 and Hg = 13. Take the densities of seawater. Determine the pressure difference between the two pipelines. (Ans: 3.8 and the manometer reading is 0. If the fluid in the pipe has a relative density of 0. Fluid Mechanics (CLB 11003) Chapter 3: Static fluid 11. If a 10 cm high portion of the ice block extends above the surface of the water.4 lbm/ft3). The specific gravities of ice and seawater are 0.88. (Ans: 10. SGwater = 1 and SGair = 0.23 kPa) Figure 7 12. respectively.6. Consider a large cubic ice block floating in seawater. determine the height of the ice block below the surface. A crane is used to lower weights into a lake for an underwater construction project. (Ans: 87.82.025. Define buoyancy.92 and 1. Determine the pressure difference between points A and B in Figure 7 (SGbenzene = 0. Determine the tension in the rope of the crane due to a 3 ft diameter spherical steel block (density = 494 lbm/ft3) when it is (a) suspended in the air and (b) completely immersed in water (density = 62.6 cm) Figure 8 . SGHg = 13. 13. SGkerosene = 0. 6980 lbf. (Ans: a). b) 6100 lbf) 14.0118.