Questions
Question 1
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Water flows horizontally from speed \(2.0\,\mathrm{m\,s^{-1}}\) to \(5.0\,\mathrm{m\,s^{-1}}\). Find \(p_1-p_2\).
Question 2
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Water is accelerated from a very wide, nearly stationary region into a horizontal pipe by a pressure drop of \(18\,\mathrm{kPa}\). Find the pipe speed.
Question 3
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A small hole is \(0.80\,\mathrm{m}\) below the surface of a large open water tank. Estimate the exit speed.
Question 4
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A liquid flows steadily with the same speed at two points. Point 2 is \(3.0\,\mathrm{m}\) higher than point 1. For water, find \(p_1-p_2\).
Question 5
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Water flows horizontally through a constriction where the area halves. If \(v_1=1.5\,\mathrm{m\,s^{-1}}\), find \(v_2\) and \(p_1-p_2\).
Question 6
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Water flows from point 1 to point 2. The speed changes from \(2.0\,\mathrm{m\,s^{-1}}\) to \(3.0\,\mathrm{m\,s^{-1}}\), and point 2 is \(4.0\,\mathrm{m}\) higher. Find \(p_1-p_2\).
Question 7
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A Pitot-style measurement in air of density \(1.2\,\mathrm{kg\,m^{-3}}\) gives stagnation pressure \(540\,\mathrm{Pa}\) above static pressure. Find the air speed.
Question 8
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A hole in a large tank is \(1.25\,\mathrm{m}\) below the water surface and \(0.80\,\mathrm{m}\) above the floor. Estimate the horizontal range of the emerging water stream.
Question 9
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A horizontal Venturi tube carries water. The wide area is four times the narrow area, and the wide-section speed is \(1.0\,\mathrm{m\,s^{-1}}\). Find the pressure drop from wide to narrow section.
Question 10
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A large open tank has a small outlet of area \(1.0\times10^{-4}\,\mathrm{m^2}\), located \(2.0\,\mathrm{m}\) below the surface. Estimate the volume flow rate from the outlet.
Question 11
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Water flows horizontally. At section 1, \(p_1=2.20\times10^5\,\mathrm{Pa}\) and \(v_1=2.0\,\mathrm{m\,s^{-1}}\). At section 2, \(v_2=7.0\,\mathrm{m\,s^{-1}}\). Find \(p_2\).
Question 12
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A water jet exits vertically upward into the atmosphere from a nozzle fed by gauge pressure \(45\,\mathrm{kPa}\). Neglect losses and inlet speed. Estimate the maximum jet height.
Question 13
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Explain why a horizontal ideal-fluid streamline that speeds up must move toward lower pressure. Use Bernoulli's equation and also state the force interpretation.
Question 14
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A horizontal pipe carries a liquid of unknown density. The speed increases from \(1.0\,\mathrm{m\,s^{-1}}\) to \(4.0\,\mathrm{m\,s^{-1}}\), and the pressure falls by \(6.0\,\mathrm{kPa}\). Find the density implied by Bernoulli's equation.
Question 15
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A siphon carries water from a large open reservoir to an outlet \(1.5\,\mathrm{m}\) below the reservoir surface. The siphon crest is \(0.80\,\mathrm{m}\) above the reservoir surface. Neglect losses and pipe-radius changes. Estimate the absolute pressure at the crest.
Question 16
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A horizontal streamline has speed \(v(s)\) along distance coordinate \(s\). Starting from Bernoulli's equation, derive \(dp/ds\) in terms of \(v\) and \(dv/ds\). Interpret the sign when the flow accelerates.
Question 17
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For horizontal incompressible flow, section 1 has area \(A_1\), speed \(v_1\), and pressure \(p_1\). Section 2 has area \(A_2\). Derive \(p_1-p_2\) in terms of \(\rho\), \(v_1\), and \(k=A_1/A_2\).
Question 18
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A tank surface area \(A_T\) is not extremely large compared with a hole area \(a\). The water surface is height \(h\) above the hole, and both surface and hole are open to the atmosphere. Derive the hole speed using continuity and Bernoulli.
Question 19
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A horizontal constriction has \(A_1/A_2=k>1\). Upstream pressure is \(p_1\), vapor pressure is \(p_v\), and density is \(\rho\). Derive the maximum upstream speed \(v_1\) that keeps the narrow-section pressure at or above \(p_v\).
Question 20
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A streamline connects points 1 and 2 in steady incompressible nonviscous flow. Derive a symbolic condition, using only \(p_1-p_2\), \(y_2-y_1\), and \(\rho\), for point 2 to have a larger speed than point 1. Interpret the condition physically.