#
Question :
61. A fountain sends water to a height of 100 : 2102179

61. A fountain sends water to a height of 100 m. What must be the pressurization (above atmospheric) of the underground water system? (1 atm = 10^{5} N/m^{2})

A. 1 atm

B. 4.2 atm

C. 7.2 atm

D. 9.8 atm

62. The Garfield Thomas water tunnel at Pennsylvania State University has a circular cross-section that constricts from a diameter of 3.6 m to the test section, which is 1.2 m in diameter. If the speed of flow is 3.0 m/s in the large-diameter pipe, determine the speed of flow in the test section.

A. 9.0 m/s

B. 18 m/s

C. 27 m/s

D. 1.0 m/s

63. A Boeing-737 airliner has a mass of 20 000 kg. The total area of the wings is 100 m^{2}. What must be the pressure difference between the top and bottom of the wings to keep the airplane up?

A. 1 960 Pa

B. 3 920 Pa

C. 7 840 Pa

D. 15 700 Pa

64. How much air must be pushed downward at 40.0 m/s to keep an 800-kg helicopter aloft?

A. 98.0 kg/s

B. 196 kg/s

C. 294 kg/s

D. 392 kg/s

65. A jet of water flowing from a hose at 15 m/s is directed against a wall. If the mass flow in the fluid stream is 2.0 kg/s, what force is the water applying to the wall if backsplash is negligible?

A. 30 N

B. 40 N

C. 65 N

D. 127 N