Question
The cylindrical tube of a spray pump has a cross-section of 8.0 cm2 one end of which has 40 fine holes each of diameter 1.0 mm. If the liquid flow inside the tube is 1.5 m/min, what is the speed of ejection of the liquid through the holes?
Solution
Area of cross-section of cylindrical tube, A = 8 cm2
Velocity of flow in the tube, v = 1.5 m/min = 2.5 cm/sec
Diameter of the hole, d = 1 mm = 0.1 cm
Area of one hole, ao = 
Total area of 40 holes, a = 40 ao = 
= 0.1 
Let v' be the velocity of the ejection of the liquid through the holes.
Using equation of continuity,
AV = av
Putting the values, we get
