A.仅与相对粗糙度有关 B.仅与雷诺数有关 C.与相对粗糙度及雷诺数均有关 D.仅与管长有关
A.1／4 B.1／3 C.1／2 D.1
A.4.5mH2O B.6.05mH2O C.5.05mH2O D.5.82mH2O
A.10.84m／s B.8.85m／s C.7.83m／s D.6.25m／s
A.19.6kPa B.29.4kPa C.205.8kPa D.117.6kPa
A.0.62 B.0.66 C.1.51 D.1.61
A.增大 B.减少 C.不变 D.不定
A.4mH2O B.6mH2O C.3.5mH2O D.2mH2O
A.1 B.0.5 C.1.5 D.2
A.19.6×104N B.20×103N C.9.8×105N D.2×105N
