Respuesta :
Answer:
0.0072 m³/s
Explanation:
Using Bernoulli's law
P₁ + 1/2ρv₁² = P₂ + 1/2ρv₂ since the pipe is horizontal
1/2ρv₂² - 1/2ρv₁² = P₁ - P₂
flow rate is constant
A₁v₁ = A₂v₂
A₁ = πr₁² = π (0.06/2)² = 0.0028278 m²
A₂ = πr₂² = π (0.0225)² = 0.00159 m²
v₁ = (A₂ / A₁)v₂
v₁ = (0.00159 m²/ 0.0028278 m²) v₂ = 0.562 v₂
substitute v₁ into the Bernoulli's equation
1/2ρv₂² - 1/2ρv₁² = P₁ - P₂
500 ( 1 - 0.3161 ) v₂² = (31.0 - 24 ) × 10³ Pa
341.924 v₂² = 7000
v₂² = 20.472
v₂ = √ 20.472 = 4.525 m/s
volume follow rate = 0.00159 m² × 4.525 m/s = 0.0072 m³/s
[tex]0.0072 \;\rm m^{3}/s[/tex]The volume flow rate at the exit of the pipe is [tex]0.0072 \;\rm m^{3}/s[/tex].
Given data:
The initial diameter of horizontal pipe is, d = 6.0 cm.
The final diameter of pipe is, d' = 4.5 cm.
The gauge pressure at inner section is, P = 31.0 kPa.
The gauge pressure at outer section is, P' = 24.0 kPa.
Applying the Bernoulli's concept, which says the total pressure energy and kinetic energy throughout the flow remains constant .
So, for the horizontal pipe, the expression is,
[tex]P + \dfrac{1}{2} \rho v^{2} = P' + \dfrac{1}{2} \rho v'^{2}[/tex] ............................................(1)
Here, [tex]\rho[/tex] is the density of water throughout the flow, which remains constant.
Now, apply the continuity equation as,
[tex]A\times v = A' \times v'\\\\(\pi/4 \times d^{2}) \times v = (\pi/4 \times d'^{2}) \times v'\\\\ d^{2} \times v = d'^{2} \times v'\\\\v/v' = 0.045^{2}/0.006^{2}\\\\v = 0.5625\times v'[/tex]
Now substitute the value in equation (1) as,
[tex]P -P' = \dfrac{1}{2} \rho v'^{2} - \dfrac{1}{2} \rho v^{2}\\\\(31 -24) \times 10^{3} \;\rm Pa = \dfrac{1}{2} \times 1000 v'^{2} - \dfrac{1}{2} \times 1000 (0.5625 v')^{2}\\v' = 4.52 \;\rm m/s[/tex]
Then the flow rate is calculated as,
[tex]Q' = A' \times v'\\\\Q' = (\pi /4) d'^{2} \times v'\\Q' = (\pi /4) \times 0.06'^{2} \times 4.52\\\\Q' = 0.0072 \;\rm m^{3}/s[/tex]
Thus, the required value of volume flow rate is, [tex]0.0072 \;\rm m^{3}/s[/tex].
Learn more about the Bernoulli's theorem here:
https://brainly.com/question/23841792
