A 6.9 cm diameter horizontal pipe gradually narrows to 5.4 cm . When water flows through this pipe at a certain rate, the gauge pressure in these two sections is 34.0 kPa and 21.0 kPa , respectively.
What is the volume rate of flow?
Express your answer using two significant figures.
Physics Help. Answer please?
2015-12-09 9:08 pm
回答 (1)
2015-12-09 10:19 pm
✔ 最佳答案
Ooh, interesting. Bernoulli:p₀ + ½ρv₀² + ρgh₀ = p₁ + ½ρv₁² + ρgh₁
and the height terms fall out ("horizontal").
Furthermore, v₀ * A₀ = v₁ * A₁ = Q = volume rate flow
v₀ * π(6.9cm)²/4 = v₁ * π(5.4cm)²
v₁ = 1.633*v₀
Then
34.0kPa + ½*1000kg/m³*v₀² = 21.0kPa + ½*1000kg/m³*(1.633v₀)²
13.0 kPa = 833kg/m³ * v₀²
v₀ = 3.95 m/s
and
Q = v₀ * A₀ = 3.95m/s * (π/4)*(0.069m)² = 0.015 m³/s
Hope this helps!
收錄日期: 2021-04-21 15:38:37
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