The $10 \mathrm{~cm}$ galvanized-steel pipe is $1000 \mathrm{~m}$ long and discharges water into the atmosphere. The pipeline has an open globe valve and four threaded elbows; $h_1=3 \mathrm{~m}$ and $h_2=15 \mathrm{~m}$. What is the discharge, and find the pressure at $A$, the midpoint of the line?

A house has a composite wall of wood, fiberglass insulation, and plaster board, as indicated in the given figure. On a cold winter day the convection heat transfer coefficients are $h_o=$ $60 \mathrm{~W} / \mathrm{m}^2 \cdot \mathrm{K}$ and $h_i=30 \mathrm{~W} / \mathrm{m}^2 \cdot \mathrm{K}$. The total wall surface area is $350 \mathrm{~m}^2$.

(a) Determine an expression in symbol form for the total thermal resistance of the wall, including inside and outside convection effects for the prescribed conditions.

(b) Determine the total heat rate through the wall.

(c) If the wind were blowing violently, raising $h_0$ to $300 \mathrm{~W} / \mathrm{m}^2 \cdot \mathrm{K}$, determine the percentage increase in the heat rate.

(d) What is the controlling resistance that determines the heat rate through the wall?

Gasoline at a temperature of $20^{\circ} \mathrm{C}$ flows through the $3$ -in.-diameter pipe at the rate of $0.002\ \mathrm{ft}^3 / \mathrm{s}$. Calculate the pressure drop that occurs along a $100$ -ft length.

A string has a length of $1.5 \mathrm{~m}$, a linear mass density $\mu=0.008 \mathrm{~kg} / \mathrm{m}$, , and a tension of $120 \mathrm{~N}$. If the air temperature is $T=22^{\circ} \mathrm{C}$, what should the length of a pipe open at hoth ends for it to have the same frequency for the $n=3$ mode?

Find the power input for a compressor that compresses helium from $150 \mathrm{kPa}$ and $20^{\circ} \mathrm{C}$ to $400 \mathrm{kPa}$ and $200^{\circ} \mathrm{C}$. Helium enters this compressor via a $0.1-\mathrm{m}^2$ pipe at a velocity of $15 \mathrm{~m} / \mathrm{s}$.

A deceased person

A pressure drop of $0.07 \mathrm{~psi}$ occurs over a section of $0.8-\mathrm{in}$.-diameter pipe transporting water at $70^{\circ} \mathrm{F}$. Determine the length of the horizontal section if the Reynolds number is $1600$ . Also, find the shear stress at the wall and the friction factor.

What must be the pressure difference between the two ends of a 1.9-km section of pipe, 29 cm in diameter, if it is to transport oil $\left(\rho=950 \mathrm{kg} / \mathrm{m}^{3}, \eta=0.20 \mathrm{Pa} \cdot \mathrm{s}\right)$ at a rate of $450 \mathrm{cm}^{3} / \mathrm{s} ?$

The hydrogen in section $A$ of the pipe is at a temperature of $60^{\circ} \mathrm{F}$ and an absolute pressure of $301\ \mathrm{lb} / \mathrm{in}^2$, whereas when it is at B, its temperature is $100^{\circ} \mathrm{F}$ and the absolute pressure is $20\ \mathrm{lb} / \mathrm{in}^2$. Find the change per unit mass in the internal energy, enthalpy, and entropy between the two sections.

The velocity distribution in a $4$-$\mathrm{cm}$-diameter pipe transporting $20^{\circ} \mathrm{C}$ water is given by $u(r)=$ $10\left(1-2500 r^2\right) \mathrm{m} / \mathrm{s}$. The shearing stress at the wall is nearest: (A) $1.0 \mathrm{~Pa}$ (B) $0.1 \mathrm{~Pa}$ (C) $0.01 \mathrm{~Pa}$ (D) $0.001 \mathrm{~Pa}$

An organ pipe is tuned to exactly 384 Hz when the temperature in the room is $20 ^ { \circ } \mathrm { C }$. Later when the air has warmed up to $25 ^ { \circ } \mathrm { C }$, the frequency is A. Greater than 384 Hz. B. 384 Hz. C. Less than 384 Hz.

Water flows steadily through a pipe of length $L$ and radius $R=75 \mathrm{~mm}$. Calculate the uniform inlet velocity, $U$, if the velocity distribution across the outlet is given by

$$u=u_{\max }\left[1-\frac{r^2}{R^2}\right]$$

and $u_{\max }=3 \mathrm{~m} / \mathrm{s}$.

Suppose the cylindrical conductor of Fig. $28-11 \mathrm{a}$ has a concentric cylindrical hollow cavity inside it (so it looks like a pipe). What can you say about $\overrightarrow{\mathbf{B}}$ in the cavity?

A circle of pollution is spreading from a broken underwater waste disposal pipe, with the radius increasing at the rate of 4 ft per minute. Find the rate of change of the area of the circle when the radius is 7 ft.