Write and produce a radio play of the Alvarez family's escape from the Dominican Republic. Base the script on the events described in the poem. Use sound effects to create suspense and enhance the listener's sense of place and event.

Why is the following situation impossible? At the Summer Olympics, an athlete runs at a constant speed down a straight track while a spectator near the edge of the track blows a note on a horn with a fixed frequency. When the athlete passes the horn, she hears the frequency of the horn fall by the musical interval called a minor third. That is, the frequency she hears drops to five-sixths its original value.

The mass of the deuterium molecule (D2) is twice that of the hydrogen molecule (H2). If the vibrational frequency of H2 is $1.30 \times 1014$ Hz, what is the vibrational frequency of D2? Assume the “spring constant” of attracting forces is the same for the two molecules.

The pitch, or frequency, of a piano note is related to its position on the keyboard by the function $F(n)=440 \cdot 2^{\frac{\pi}{2}}$, where $F$ is the frequency of the sound waves in cycles per second and $n$ is the number of piano keys above or below Concert $A$, as shown. If $n=0$ at Concert A, which of the instruments shown in the diagram can sound notes at the given frequency?

a. 590 b. 120 c. 1440 d. 2093

A parallel-plate guide is partially filled with two lossless dielectrics where $\epsilon_{r 1}^{\prime}=4.0, \epsilon_{r 2}^{\prime}=2.1,$ and d = 1 cm. At a certain frequency, it is found that the $TM_1$ mode propagates through the guide without suffering any reflective loss at the dielectric interface. (a) Find this frequency. (b) Is the guide operating at a single TM mode at the frequency found in part (a)?

A pedestrian waiting for the light to change at an intersection hears a car approaching with its horn blaring. The car's horn produces sound with a frequency of 381 Hz, but the pedestrian hears a frequency of 389 HZ. How fast is the car moving?

Piano tuners sometimes start by striking a tuning fork and then the corresponding piano key. If the tuning fork and piano note each have frequency 8, then the resulting sound is sin 8t+sin 8t. Graph this. If the piano is slightly out-of-tune at frequency 8.1, the resulting sound is sin 8t+sin 8.1t. Graph this and explain how the piano tuner can hear the small difference in frequency.

A radio transmitter broadcasts uniformly in all directions with a power output of $50 \mathrm{~kW}$. What is the time-average Poynting flux $50 \mathrm{~km}$ from the transmitter? What is the amplitude of the electric field there?

Lee la siguiente declaración y traduce el pronombre neutro entre paréntesis.

• Este reloj está roto, la computadora no funcionea y el radio no recibe muchas estaciones.
• ¡________ (this) es un desastre!

For each data set. a. determine a frequency distribution. b. obtain a relative-frequency distribution. c. construct a frequency histogram based on your result from part (a). d. construct a relative-frequency histogram based on your results from part (b). Use cutpoint grouping with a first class of 40-under 46.

$$\begin{array}{lllll} \hline 50.0 & 53.4 & 44.5 & 55.2 & 51.2 \\ 56.8 & 52.5 & 51.6 & 48.6 & 56.9 \\ 54.3 & 51.0 & 43.5 & 57.5 & 65.4 \\ 41.6 & 57.8 & 54.2 & 52.5 & 50.7 \\ \hline \end{array}$$

A standing wave is set up in a string of variable length and tension by a vibrator of variable frequency. Both ends of the string are fixed. When the vibrator has a frequency $f_A$, in a string of length $L_A$ and under tension $T_A, n_A$ antinodes are set up in the string. If the frequency is tripled and the length of the string is halved, by what factor should the tension be changed so that twice as many antinodes are produced?

An antique dealer has 24 clock radios to sell at a 12-hour-long antique-radio sale. Use the graph to complete the table.

What happens to the total number of radios every two hours?

A ship at sea is 70 miles from one radio transmitter and 130 miles from another. The angle formed by the rays from the ship to the transmitters measures $130^{\circ} .$ How far apart are the transmitters?

Solve the given initial-value problems. For each problem determine the circular frequency, the frequency, the period, and the amplitude of the solution.

$$\begin{aligned} y^{\prime \prime} +4 y =0 \\ y(0)=2 \\ y^{\prime} (0)= -5 \\ \end{aligned}$$