Fluid Mechanics 7th. Edition by Frank White | 9780073529349 | 73529346 | Holooly

Fluid Mechanics [EXP-65260]

157 SOLVED PROBLEMS

Question: 10.4

(a) What are the best dimensions y and b for a rectangular brick channel designed to carry 5 m^3/s of water in uniform flow with S0 = 0.001? (b) Compare results with a half-hexagon and semicircle.

Verified Answer:

Part (a) From Eq. (10.26), A = 2

y^2

...

Question: 6.2

A 1/2-in-diameter water pipe is 60 ft long and delivers water at 5 gal/min at 20°C. What fraction of this pipe is taken up by the entrance region?

Verified Answer:

Convert Q = (5 gal/min)

\frac{0.00223 ft^3/...

Question: 3.16

A 10-cm fire hose with a 3-cm nozzle discharges 1.5 m^3/min to the atmosphere. Assuming frictionless flow, find the force FB exerted by the flange bolts to hold the nozzle on the hose.

Verified Answer:

We use Bernoulli’s equation and continuity to find...

Question: 2.12

A barge has a uniform rectangular cross section of width 2L and vertical draft of height H, as in Fig. E2.12. Determine (a) the metacentric height for a small tilt angle and (b) the range of ratio L/H for which the barge is statically stable if G is exactly at the waterline as shown.

Verified Answer:

If the barge has length b into the paper, the wate...

Question: 2.11

A block of concrete weighs 100 lbf in air and “weighs” only 60 lbf when immersed in fresh water (62.4 lbf/ft3). What is the average specific weight of the block?

Verified Answer:

A free-body diagram of the submerged block (see Fi...

Question: 1.1

A body weighs 1000 lbf when exposed to a standard earth gravity g 32.174 ft/s2 . (a) What is its mass in kg? (b) What will the weight of this body be in N if it is exposed to the moon’s standard acceleration gmoon 1.62 m/s2 ? (c) How fast will the body accelerate if a net force of 400 lbf is applied to it on the moon or on the earth?

Verified Answer:

We need to find the (a) mass; (b) weight on the mo...

Question: 4.4

A centrifugal impeller of 40-cm diameter is used to pump hydrogen at 15 C and 1-atm pressure. Estimate the maximum allowable impeller rotational speed to avoid compressibility effects at the blade tips.

Verified Answer:

• Assumptions: The maximum fluid velocity is appro...

Question: 1.9

A certain torpedo, moving in fresh water at 10°C, has a minimum-pressure point given by the formula p_{min} = p_0 – 0.35 ρV^2 (1) where p_0 = 115 kPa, ρ is the water density, and V is the torpedo velocity. Estimate the velocity at which cavitation bubbles will form on the torpedo. The constant 0.35

Verified Answer:

• Assumption: Cavitation bubbles form when the min...

Question: 3.12

A classic example of an accelerating control volume is a rocket moving straight up, as in Fig. E3.12. Let the initial mass be M0, and assume a steady exhaust mass flow

Verified Answer:

The appropriate control volume in Fig. E3.12 enclo...

Question: 1.11

A commercial airplane flies at 540 mi/h at a standard altitude of 30,000 ft. What is its Mach number?

Verified Answer:

• Approach: Find the “standard” speed of sound; di...

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