A pipe is running full of water. At a point A it tapers from 400cm2  cross-sectional area to 200cm2  at other point B. If the pressure difference between A and B is 30cm of water column. The rate of volume of water through the pipes is [g=10m/s2]

A1v1=A2v2 400v1=200v2 v2=2v1 p1−p2=ρ2(v22−v12) hρg=ρ2(v22−v12)                                         30×10−2×103×10=10002((2v1)2−v12)                                   3×103=500(4v12−v12)⇒3v12=3000500                                                v12=1000500⇒v1=2                                                                Rate of flow =A1v1=400×10−4×2  =56.56×10−3=56.5 liters