Test 2

1. If force, length, and time are selected as the three fundamental dimensions, what are the dimensions on mass?  
2. Calculate the weight of the column of air contained above a 1-m2 area of atmospheric air from sea level to the top of the atmosphere.

3. The specific gravity of a liquid is 0.75. What height of that liquid is needed to provide a pressure difference of 200 kPa?

4. Assume a pressure of 100 kPa absolute at ground level. What is the pressure difference between the top of a 3-m-high wall on the outsidewhere the temperature is 20°C and on the inside of a house where the temperature is 22°C? (This difference results in infiltration even if no windis present.)

3. The pressure at the nose of a small airplane is given by p = ρV 2 /2, where r is the density of air. A U-tube manometer measures 25 cm of water. Determine the airplane’s speed if it is flying at an altitude of 4000 m.

4. A submersible has a viewing window that is 60 cm in diameter. Determine the pressure force of the water on the window if the center of the window is 30 m below the surface and the window is at a 45° angle.

5. An object with a volume of 1200 cm3 weighs 20 N. What will it weigh when submerged in water?

6. A 1-m-high, 2-m-long enclosed tank is filled with water and accelerated horizontally at 6 m/s2. If the top of the tank has a small slit across the back, calculate the distance from the front of the tank on the bottom where the pressure is zero.

7. Estimate the force acting on the bottom of the 80-cm-wide tank of Prob. 6.

8. Convert 230 kPa to millimeters of mercury, inches of mercury, and feet of water.

9. All fluids in Figure are at 20°C.If p = 1900 psf at point A, determine the pressures at B, C, and D in psf.

10. All fluids in Figure are at 20°C. If atmospheric pressure = 101.33 kPa and the bottom pressure is 242 kPa absolute, what is the specific gravity of fluid X?