Question
Question: The cylindrical tube of a spray pumps has a cross-section of \(6 \mathrm {~cm} ^ { 2 }\) one of whic...
The cylindrical tube of a spray pumps has a cross-section of 6 cm2 one of which has 50 holes each of diameter 1 mm. If the liquid flow inside the tube is 1.2 m per minute, then the speed of ejection of the liquid through the holes is
A
(a) 2.1 m s−1
A
(b) 0.31 m s−1
A
(c) 0.96 m s−1
A
(d) 3.4 m s−1
Explanation
Solution
(b) Here, area of cross section of tube
Number of holes = 50
Diameter of each hole D = 1 mm =10−3 m
Radius of hole,
Area of cross section of each hole
=πr2=π(5×10−4)2 m2
Total area of cross section of 50 holes,
Speed of liquid inside the tube,
=601.2 m s−1=0.02 m s−1
Let the velocity of ejection of the liquid through the hole
As
Or