A.φ80 4 mm B.φ108 4mm C.φ50 3 mm D.φ150 4 mm
A.3.14 m/s B.1.77m/s C.2.56 m/s D.5.08 m/s
A.質(zhì)量流量ωs1=ωs2 B.質(zhì)量流量ωs=u1A1ρ1=u2A2ρ2 C.體積流量Vs= u1A1= u2A2 D.體積流量Vs= u1A1= u2A2 而ωs1≠ωs2