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 1.5m min -1. What is the speed of ejection of the liquid through the holes?
Area of cross-section of the spray pump, A1 = 8 cm2 = 8 × 10 - 4 m2
Number of holes, n = 40
Diameter of each hole, d = 1 mm = 1 × 10 - 3m
Radius of each hole, r = \(\frac{d}{2}\) = 0.5 × 10 - 3m
Area of cross-section of each hole, a = πr2 = π(0.5 × 10 - 3)2 m2
Total area of 40 holes, A2 = n × a
= 40 × π (0.5 × 10–3) 2 m2
= 31.41 × 10–6 m2
Speed of flow of liquid inside the tube, V1 = 1.5 m / min = 0.025 m / s
Speed of ejection of liquid through the holes = V2
According to the law of continuity, we have
A1V1 = A2V2
\(V_2 =\frac{ A_1V_1 }{ A_2}\)
\(= \frac{8 × 10 ^{- 4} × 0.025 }{ 31.61 × 10 ^{- 6} }\)
= 0.633 m / s
Therefore, the speed of ejection of the liquid through the holes is 0.633 m / s.
Find the mean deviation about the mean for the data 38, 70, 48, 40, 42, 55, 63, 46, 54, 44.
In fluid dynamics, Bernoulli's principle states that an increase in the speed of a fluid occurs simultaneously with a decrease in static pressure or a decrease in the fluid's potential energy. The principle is named after Daniel Bernoulli who published it in his book Hydrodynamica in 1738.
