Radius of each circular opening,
r1=1mm =10−3m ∴ Cross-sectional area of each opening,
A1=πr12=π×10−6m2 Radius of the pipe,
r2=2cm=0.02m ∴ Cross-sectional area of pipe,
A2=πr22 =π×(0.02)2m2 The speed of water in the pipe,
v2=25cm∕s =0.25m∕s Let the speed of water when it exits from the circular openings is
v1m∕s.
Number of circular openings,
n=25 As, the flow rate is always constant.
∴25A1v1=A2v2 ⇒v1=v2 =×=4m∕s