19. Fluid Mechanics

In a horizontal pipe where water flows steadily with negligible viscous effects, which of the following statements about the speed and cross-sectional area at two points along the pipe is correct according to the continuity equation?

A horizontal pipe has a cross-sectional area $A_1$ at one end and $A_2$ at the other. Water enters the pipe at speed $v_1$ through the end with area $A_1$. What is the speed of the water, $v_2$, at the end with area $A_2$ according to the continuity equation?

When water flows through a horizontal pipe bend and discharges into the atmosphere, which of the following statements about the pressure at the exit ($p$, discharge point) is correct?

A drinking fountain shoots water about 12 cm up in the air from a nozzle of diameter 0.60 cm (Fig. 13–67). The pump at the base of the unit (1.1 m below the nozzle) pushes water into a 1.2-cm-diameter supply pipe that goes up to the nozzle. What gauge pressure does the pump have to provide? Ignore the viscosity; your answer will therefore be an underestimate.

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Which of the following best describes the effect of a blockage in the static port of a Pitot-static tube when measuring the airspeed of a fluid flow?

(II) A viscometer consists of two concentric cylinders, 10.20 cm and 10.60 cm in diameter. A liquid fills the space between them to a depth of 15.0 cm. The outer cylinder is fixed, and a torque of 0.024 m N keeps the inner cylinder turning at a steady rotational speed of 57 rev/min. What is the viscosity of the liquid?

Which term best describes an equipment or process powered by compressed air?

When air is drawn into a wind tunnel used for testing automobiles, which principle explains why the speed of the air increases as it passes through a narrower section of the tunnel?

Which of the following actions is most likely to cause a laminar flow in a pipe to become turbulent?

A container is filled with oil and is open to the atmosphere on the left side. If the oil flows steadily from the left (point $1$) to the right (point $2$) through a horizontal pipe of varying cross-sectional area, which of the following statements about the speed of the oil at points $1$ and $2$ is correct according to the continuity equation?

If water flows through a horizontal pipe with a speed of $4.0m/s$ at point 1 where the cross-sectional area is $0.020m^2$, what is the speed of the water at point 2 where the cross-sectional area is $0.010m^2$? Assume the flow is steady and incompressible.

(III) A long vertical hollow tube with an inner diameter of 1.00 cm is filled with SAE 10 motor oil. A 0.900-cm-diameter, 30.0-cm-long 150-g rod is dropped vertically through the oil in the tube. What is the maximum speed attained by the rod as it falls?

You are watering your lawn with a hose when you put your finger over the hose opening to increase the distance the water reaches. If you are holding the hose horizontally, and the distance the water reaches increases by a factor of 4, what fraction of the hose opening did you block?

When water flows through a pipe that gets narrower, what happens to the speed of the water as it enters the narrower section according to the continuity equation $Av=\mathrm{constant}$?

A pitot tube is used to measure which of the following quantities in a fluid flow?