Chapter 6 Test Questions

1. A liquid has density 950 kg/m³. Calculate the pressure at 10 m depth.
2. Water flows through a horizontal pipe of cross-section 0.05 m² at 4 m/s. If the pipe narrows to 0.01 m², find the speed in the narrow section.
3. A horizontal pipe has water moving at 3 m/s with pressure 1.0 × 10⁵ Pa. If the velocity increases to 7 m/s, determine the new pressure (ρ = 1000 kg/m³).
4. An object floats in a liquid of density 850 kg/m³. If 60% of its volume is submerged, find the density of the object.
5. A U-tube contains two liquids of densities 800 kg/m³ and 1000 kg/m³. If one column is 0.5 m high, find the height of the other column.
6. Explain using Bernoulli’s principle why the pressure above an airplane wing is lower than below.
7. A vertical water column is 8 m high. Find the pressure at its base in kPa.
8. Oil flows through a pipe at a rate of 0.06 m³/s. If the pipe’s cross-section is 0.02 m², calculate the oil’s speed.
9. A pipe carries water at 2 m/s in a wide section. In a narrow section, velocity is 5 m/s. Determine the pressure difference between the sections (ρ = 1000 kg/m³).
10. Discuss why Bernoulli’s equation cannot be applied directly to viscous, turbulent flows.