Water (ρ = 1000 kg/m³) flows at 4 m/s through a pipe with an inner diameter of 150 mm. Find the mass flow rate ṁ.
Continuity & Bernoulli worksheet with answers
A water line must carry 6 L/s. To limit noise and wear, the mean velocity should be 2.5 m/s. Find the inner pipe diameter d needed.
Water flows through a horizontal pipe that narrows from 200 mm to 75 mm. In the wide section the pressure is 380 kPa and the velocity is 2 m/s. Ignoring losses, find the pressure p2 in the narrow section.
A pitot-static tube in a wind tunnel reads a difference of 1400 Pa between the stagnation pressure and the static pressure. The air density is 1.2 kg/m³. Find the air speed v.
A horizontal venturi meter (inlet 100 mm, throat 50 mm) carries water. A mercury U-tube manometer connected between the inlet and the throat shows a level difference of 230 mm. The discharge coefficient is 0.96. Find the flow rate Q. Use ρ = 1000 kg/m³ for water, 13 600 kg/m³ for mercury and g = 9.81 m/s².
A hose with an inner diameter of 20 mm siphons water from an open tank. The highest point C of the hose is 3 m above the water surface, and the outlet (open to the air) is 2.5 m below the water surface. Ignore losses and take g = 9.81 m/s². Find the flow rate Q.
Answer key
- 1. ṁ = 70.69 kg/s
- 2. d = 55.28 mm
- 3. p2 = 280.9 kPa
- 4. v = 48.3 m/s
- 5. Q = 14.68 L/s
- 6. Q = 2.2 L/s
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