Which of the following environments would likely have clasts smaller than sand?

A. a weak current

B. steep slopes

C. dunes formed by wind

D. all of these

Under certain conditions, the wind speed S, in miles per hour, of a tornado at a distance d feet from its center can be approximated by the function

$S(a, d, V)=\frac{a V}{0.51 d^2}$,

where $a$ is a constant that depends on certain atmospheric conditions and $V$ is the approximate volume of the tornado, in cubic feet. Approximate the wind speed 100 ft from the center of a tornado when its volume is $1,600,000 \mathrm{ft}^3$ and $a=0.78$.

Complete each of the following sentences by adding an indefinite pronoun that agrees with the verb.

Example: Unfortunately, $\underline{\color{#c34632}{none}}$ of the quiche is left.

____________________ in the backyard has been rattling in the wind.

What is the maximum power that can be expected from a windmill 30 m in diameter in a wind of 50 km/h? Assume air density 1.225 kg/m$^{3}$.

A $55.0~\text{kg}$ ice skater glides along the ice, heading due north at $4.00~\text{m}/\text{s}$. The ice has a small coefficient of static friction, to prevent the skater from slipping sideways but pk Suddenly; wind from the northeast exerts a force of $50~\text{N}$ on the skater:

Use work and energy to find the skater's speed after gliding $100~\text{m}$ in this wind. Express your answer with the appropriate units.

The wind-chill temperature W measures how cold people feel (based on the rate of heat loss from exposed skin) when the outside temperature is

$$T ^ { \circ } \mathrm { C }$$

(with

$$T \leq 10 )$$

and wind velocity is v m/s (with

$$v \geq 2 ):$$

$$W = 13.1267 + 0.6215 T - 13.947 v ^ { 0.16 } + 0.486 T v ^ { 0.16 }$$

Calculate

$$\partial W / \partial v$$

at (T, v) = (-10, 15) and use this value to estimate

$$\Delta W$$

if

$$\Delta v = 2.$$

A wind "farm" consists of 20 Darrieus turbines, each $15 \mathrm{~m}$ high. The total output from the turbines is to be $2 \mathrm{MW}$ in a wind of $20 \mathrm{~m} / \mathrm{s}$ and an air density of $1.2 \mathrm{~kg} / \mathrm{m}^3$. The Darrieus turbine shown has the shape of an arc of a circle. Find the minimum width, $W$, of the turbine required to provide this power output.

The wind was blowing quite strongly when Jenny was baby-sitting. She was outside with the children, and they were throwing their large plastic ball up into the air. The wind blew the ball so that it landed approximately 3 feet east and 4 feet north of where it was thrown into the air. If

$$\left[\begin{array}{l} x \\ y \end{array}\right]$$

represents the original location of the ball, write a matrix that represents the location of the translated ball.

The wave heights h in the open sea depend on the speed v of the wind and the length of time t that the wind has been blowing at that speed. Values of the function h=f(v, t) are recorded in feet in the following table.

What appears to be the value of the following limit?

$$\lim _{t \rightarrow \infty} \frac{\partial h}{\partial t}$$

The number of horsepower H required to overcome wind drag on a certain automobile is approximated by

$$H(s)=0.002 s^2+0.05 s-0.029, \quad 0 \leq s \leq 100$$

where s is the speed of the car (in miles per hour).

(a) Use a graphing utility to graph the function.

(b) Graphically estimate the maximum speed of the car if the power required to overcome wind drag is not to exceed 10 horsepower. Verify your result algebraically.

The speed s of an airplane is given by s = d/t, where d represents the distance and t is the time.

a. A plane flies 700 miles from New York to Chicago at a speed of 360 mi/h. Find the time for the trip.

b. On the return trip from Chicago to New York, a tail wind helps the plane move faster. The total flying time for the round trip is 3.5 h. Find the speed of the tail wind.

A plane flies at a speed of 370mph on a benring of S45$^{\circ}$E. Relative to the ground, the plane's speed is measured as 345mph with a tue bearing of S40$^{\circ}$E. Rounding to the nearest whole unit, a. Express the velocity of the plane $v_p$ relative to the air in terms of $i$ and $j$. b. Express the true velocity of the plane $v_T$ in lerms of $i$ and $j$. c. Express the velocity of the wind $v_w$ in terms of $i$ and $j$ and find the speed of the wind.

The Bernoulli effect can have important consequences for the design of buildings. For example, wind can blow around a skyscraper at remarkably high speed, creating low pressure. The higher atmospheric pressure in the still air inside the buildings can cause windows to pop out. As originally constructed, the John Hancock building in Boston popped window panes, which fell many stories to the sidewalk below. (a) Suppose that a horizontal wind blows in streamline flow with a speed of $11.2 \mathrm{~m} / \mathrm{s}$ outside a large pane of plate glass with dimensions $4.00 \mathrm{~m} \times 1.50 \mathrm{~m}$. Assume the density of the air to be uniform at $1.30 \mathrm{~kg} / \mathrm{m}^3$. The air inside the building is at atmospheric pressure. What is the total force exerted by air on the window pane? (b) What If If a second skyscraper is built nearby, the air speed can be especially high where wind passes through the narrow separation between the buildings. Solve part (a) again if the wind speed is $22.4 \mathrm{~m} / \mathrm{s}$, twice as high.

Write the letter for the word that best completes given sentence.

A steady wind is a....... to sailors.

a. boon

b. bane

c. toxin

d. vitiation