#
Question :
56. Water (density = 1 ´ 103 kg/m3) flows at : 2102178

56. Water (density = 1 ´ 10^{3} kg/m^{3}) flows at 10 m/s through a pipe with radius 0.030 m. The pipe goes up to the second floor of the building, 2.0 m higher, and the pressure remains unchanged. What is the radius of the pipe on the second floor?

A. 0.046 m

B. 0.034 m

C. 0.015 m

D. 0.012 m

57. Air pressure is 1.0 ´ 10^{5} N/m^{2}, air density is 1.3 kg/m^{3}, and the density of soft drinks is 1.0 ´ 10^{3} kg/m^{3}. If one blows carefully across the top of a straw sticking up 0.100 m from the liquid in a soft drink can, it is possible to make the soft drink rise half way up the straw and stay there. How fast must the air be blown across the top of the straw?

A. 76 m/s

B. 27 m/s

C. 19 m/s

D. 0.99 m/s

58. A hole is poked through the metal side of a drum holding water. The hole is 18 cm below the water surface. What is the initial speed of outflow?

A. 1.9 m/s

B. 2.96 m/s

C. 3.2 m/s

D. 3.5 m/s

59. Water comes down the spillway of a dam from an initial vertical height of 170 m. What is the highest possible speed of the water at the end of the spillway?

A. 15 m/s

B. 25 m/s

C. 58 m/s

D. 1 370 m/s

60. Water pressurized to 3 ´ 10^{5} Pa is flowing at 5.0 m/s in a pipe which contracts to 1/3 of its former area. What are the pressure and speed of the water after the contraction? (Density of water = 1 ´ 10^{3} kg/m^{3}.)

A. 2 ´ 10^{5} Pa, 15 m/s

B. 3 ´ 10^{5 }Pa, 10 m/s

C. 3 ´ 10^{5} Pa, 15 m/s

D. 4 ´ 10^{5 }Pa, 1.5 m/s