what is the history graph for this wave at x = 2 m for t = 0 s to 8 s ?
Problem ane
The wave speed on a cord under tension is 200 m/s. What is the speed if the tension is doubled?
Sheh Lit C.
University of Washington
Trouble ii
The moving ridge speed on a string is 150 m/southward when the tension is 75.0 N. What tension will give a speed of 180 m/s?
Sheh Lit C.
University of Washington
Trouble 3
The back wall of an auditorium is 26.0 thousand from the stage. If you are seated in the middle row, how much fourth dimension elapses betwixt a sound from the stage reaching your ear directly and the same sound reaching your ear afterward reflecting from the back wall?
Sheh Lit C.
University of Washington
Problem iv
Bats sense objects in the dark past echolocation, in which they emit very brusk pulses of audio and so listen for their echoes off the objects. A bat is flying directly toward a wall 50 thousand abroad when information technology emits a pulse. 0.28 s later information technology receives the pulse. What is the bat's speed?
Sheh Lit C.
University of Washington
Problem five
A scientist measures the speed of sound in a monatomic gasto exist 449 m/southward at 20°C. What element does this gas consist of?
Sheh Lit C.
University of Washington
Problem half dozen
A medical ultrasound imaging organisation sends out a steady stream of very short pulses. To simplify analysis, the reflection of one pulse should be received before the adjacent is transmitted. If the arrangement is being used to create an prototype of tissue 12 cm below the skin, what is the minimum time between pulses?
How many pulses per 2nd does this stand for to?
Sheh Lit C.
Academy of Washington
Problem 7
An earthquake 45 km from a city produces P and S waves that travel outward at 5000 and 3000 g/s, respectively. In one case city residents feel the shaking of the P wave, how much time practice they have before the S moving ridge arrives?
Sheh Lit C.
University of Washington
Problem 8
A stationary boat in the ocean is experiencing waves from a tempest. The waves move at 56 km/h and have a wavelength of 160 m, both typical values. The boat is at the crest of a wave. How much time elapses until the boat is first at the trough of a wave?
Sheh Lit C.
University of Washington
Problem nine
Effigy $\mathrm{P} 15.ix$ is a snapshot graph of a wave at $t=0 \mathrm{s}$. Draw the history graph for this wave at $x=6 \mathrm{one thousand},$ for $t=0 \mathrm{s}$ to $half dozen \mathrm{s}$.
Sheh Lit C.
Academy of Washington
Problem ten
Figure Q15.10 shows a history graph and a snapshot graph for
a wave pulse on a string. They describe the same wave from
2 perspectives.
a. In which management is the moving ridge traveling? Explain.
b. What is the speed of this wave?
Sheh Lit C.
University of Washington
Problem 11
Rank in social club, from largest to smallest, the wavelengths $\lambda_{i}$ to $\lambda_{3}$ for audio waves having frequencies $f_{1}=100 \mathrm{Hz}, f_{two}=1000 \mathrm{Hz}$ and $f_{3}=ten,000 \mathrm{Hz}$. Explain.
Sheh Lit C.
University of Washington
Problem 12
Figure P15.12 is a history graph at ten = 0 yard of a moving ridge moving to the right at 1 thousand/s. Draw a snapshot graph of this wave at t = 1 s.
Sheh Lit C.
University of Washington
Problem thirteen
2 Figure $P 15.xiii$ is a history graph at $ten=ii \mathrm{one thousand}$ of a moving ridge moving to the left at $1 \mathrm{m} / \mathrm{s}$. Draw the snapshot graph of this wave at $t=0 \mathrm{s}$
Problem fourteen
| Figure P15.fourteen shows history graphs of two different points on a cord as a wave pulse moves forth the cord. The blue curve is the history graph for the point at x = 1.0 cm, and the green bend is for the indicate at x = -3.0 cm. What is the velocity (including the correct sign for its direction) of this moving ridge?
Sheh Lit C.
Academy of Washington
Problem 15
A sinusoidal moving ridge has catamenia 0.20 s and wavelength two.0 thou. What is the wave speed?
Sheh Lit C.
University of Washington
Problem sixteen
A sinusoidal wave travels with speed 200 m/s. Its wavelength is iv.0 m. What is its frequency?
Sheh Lit C.
University of Washington
Problem 17
The motion detector used in a physics lab sends and receives 40 kHz ultrasonic pulses. A pulse goes out, reflects off the object being measured, and returns to the detector. The lab temperature is twenty°C.
a. What is the wavelength of the waves emitted by the motion
detector?
b. How long does it take for a pulse that reflects off an object
2.5 thou abroad to brand a round trip?
Sheh Lit C.
University of Washington
Problem 18
The displacement of a wave traveling in the positive $x$ -management is $y(x, t)=(3.5 \mathrm{cm}) \times \cos (ii.7 x-92 t),$ where $ten$ is in $\mathrm{m}$ and $t$ is in $\mathrm{southward}$. What are the
(a) frequency,
(b) wavelength, and
(c) speed of this wave?
Sheh Lit C.
University of Washington
Problem 19
3 A traveling wave has displacement given past $y(x, t)=$ $(2.0 \mathrm{cm}) \times \cos (2 \pi ten-4 \pi t),$ where $x$ is measured in $\mathrm{cm}$ and $t$ in $\mathrm{s}$
a. Draw a snapshot graph of this moving ridge at $t=0$ southward.
b. On the same set of axes, use a dotted line to show the snaphbot graph of the wave at $t=1 / eight \mathrm{s}$
What is the speed of the wave?
Sheh Lit C.
Academy of Washington
Trouble 20
Figure $P xv.20$ is a snapshot graph of a wave at $t=0$ s. What are the aamplitude, wavelength, and frequency of this moving ridge?
Sheh Lit C.
University of Washington
Problem 21
The probe used in a medical ultrasound examination emits sound waves in air that have a wavelength of 0.12 mm. What is the wavelength of the sound waves in the patient?
A. 0.027 mm B. 0.12 mm C. 0.26 mm D. 0.54 mm
Sheh Lit C.
University of Washington
Problem 21
Figure P15.21 is a history graph at x = 0 yard of a wave moving to the right at 2 yard/s. What are the amplitude, frequency, and
wavelength of this wave?
Sheh Lit C.
University of Washington
Problem 22
Ultrasound tin can be used to deliver free energy to tissues for therapy. It tin can penetrate tissue to a depth approximately 200 times its wavelength. What is the approximate depth of penetration of ultrasound at a frequency of 5.0 MHz?
A. 0.29 mm B. ane.4 cm C. 6.2 cm D. 17 cm
Sheh Lit C.
University of Washington
Problem 22
Figure P15.22 shows snapshot (left) and history (right) graphs for a wave traveling on a string. The snapshot graph shows the wave at t = 0 s; the history graph shows the deportation of the indicate on the cord at x = 1.5 cm, indicated by the dot in the snapshot graph. What is the speed of the wave, and in
which direction is it traveling?
Sheh Lit C.
University of Washington
Problem 23
A sinusoidal moving ridge traveling on a string has a period of 0.20 due south, a wavelength of 32 cm, and an amplitude of 3 cm. The speed of this wave is
A. 0.threescore cm/s. B. 6.4 cm/s. C. 15 cm/s. D. 160 cm/s.
Sheh Lit C.
University of Washington
Trouble 23
A sinusoidal wave moving to the left has a wavelength of $5.0 \mathrm{cm}$ and a frequency of $l \mathrm{Hz}$ At $t=0 \mathrm{s},$ the wave has a crest at $x=0 \mathrm{cm} .$ What is the earliest time after $t=0 \mathrm{s}$ at which at that place is a crest at the position $10=three.0 \mathrm{cm} ?$
Sheh Lit C.
University of Washington
Problem 24
Two strings of unlike linear density are joined together and pulled taut. A sinusoidal moving ridge on these strings is traveling to the correct, as shown in Effigy Q15.24. When the moving ridge goes across the boundary from string 1 to cord 2, the frequency is unchanged. What happens to the velocity?
A. The velocity increases.
B. The velocity stays the same.
C. The velocity decreases.
Sheh Lit C.
Academy of Washington
Trouble 24
People with very adept pitch bigotry can very quickly determine what note they are listening to. The note on the musical scale called C6 (two octaves above middle C) has a frequency of 1050 Hz. Some trained musicians can identify this note after hearing just 12 cycles of the wave. How much fourth dimension does this correspond to?
Sheh Lit C.
Academy of Washington
Problem 25
You stand at x = 0 m, listening to a sound that is emitted at frequency fs. Figure Q15.25 shows the frequency you hear during a four-2nd interval. Which of the following describes the motion of the sound source?
A. It moves from left to right and passes you at t = 2 s.
B. Information technology moves from right to left and passes you at t = 2 s.
C. It moves toward you but doesn't reach yous. Information technology and so reverses
direction at t = 2 s.
D. It moves away from y'all until t = ii s. Information technology then reverses management and moves toward you but doesn't attain you.
Sheh Lit C.
University of Washington
Trouble 25
A dolphin emits ultrasound at 100 kHz and uses the timing of reflections to determine the position of objects in the water. What is the wavelength of this ultrasound?
Sheh Lit C.
University of Washington
Trouble 26
Elephants can communicate over distances as far as half dozen km by using very low-frequency sound waves. What is the wavelength of a ten Hz sound wave emitted past an elephant?
Sheh Lit C.
University of Washington
Problem 27
a. What is the frequency of blue light that has a wavelength
of 450 nm?
b. What is the frequency of red light that has a wavelength
of 650 nm?
Sheh Lit C.
University of Washington
Problem 28
Research vessels at sea can create images of their surroundings by sending out audio waves and measuring the time until they detect echoes. This image of a shipwreck on the bounding main bottom was made from the surface with 600 kHz ultrasound.
a. What was the wavelength?
b. How deep is the shipwreck if echoes were detected 0.42 s
later on the audio waves were emitted?
Sheh Lit C.
University of Washington
Problem 29
A bullet shot from a rifle travels at 1000 m/due south. What is the elapsed fourth dimension between when the bullet strikes a target 500 thousand away, and when the sound of the gunshot reaches the target?
Sheh Lit C.
University of Washington
Problem 30
a. An FM radio station broadcasts at a frequency of
101.three MHz. What is the wavelength?
b. What is the frequency of a sound source that produces
the aforementioned wavelength in 20°C air?
Sheh Lit C.
University of Washington
Trouble 31
Sound is detected when a audio moving ridge causes the eardrum to vibrate (encounter Figure 14.26 ). Typically, the diameter of the eardrum is about $8.four \mathrm{mm}$ in humans. When someone speaks to you in a normal tone of voice, the audio intensity at your ear is approximately $1.0 \times 10^{-six} \mathrm{W} / \mathrm{m}^{2} .$ How much energy is delivered to your eardrum each second?
Sheh Lit C.
Academy of Washington
Problem 32
At a rock concert, the sound intensity 1.0 m in front end of the bank of loudspeakers is 0.10 Due west/m2 .A fan is 30 m from the loudspeakers. Her eardrums have a bore of eight.4 mm. How much audio energy is transferred to each eardrum in ane.0 second?
Sheh Lit C.
Academy of Washington
Problem 33
Ill The intensity of electromagnetic waves from the sun is $1.4 \mathrm{kW} / \mathrm{chiliad}^{two}$ but above the earth's atmosphere. Eighty per centum of this reaches the surface al apex on a articulate summertime 24-hour interval. Suppose you model your dorsum every bit a $30 \mathrm{cm} \times 50 \mathrm{cm}$ rectangle. How many joules of solar energy autumn on your dorsum as you lot work on your tan for $1.0 \mathrm{h} ?$
Sheh Lit C.
University of Washington
Problem 34
A sun-similar star is barely visible to naked-cye observers on earth when it is a distance of 7.0 low-cal years, or $6.vi \times x^{16} \mathrm{m},$ away. The sunday emits a ability of $3.8 \times ten^{28} \mathrm{Due west}$. Using this information, at what altitude would a candle that emits a power of $0.20 \mathrm{W}$ just be visible?
Sheh Lit C.
University of Washington
Trouble 35
A large solar panel on a spacecraft in world orbit produces 1.0 kW of power when the panel is turned toward the sunday. What power would the solar jail cell produce if the spacecraft were in orbit around Saturn, ix.5 times as far from the sun?
Sheh Lit C.
University of Washington
Problem 36
| Solar cells catechumen the free energy of incoming low-cal to electrical energy; a skilful quality prison cell operates at an efficiency of 15%. Each person in the United States uses energy (for lighting, heating, transportation, etc.) at an average rate of eleven kW. Although sunlight varies with season and fourth dimension of twenty-four hour period, solar energy falls on the United States at an average intensity of 200 W/m2 . Assuming you live in an average location, what total solar-cell area would y'all need to provide all of your energy needs with energy from the sun?
Sheh Lit C.
Academy of Washington
Problem 37
LASIK center surgery uses pulses of laser calorie-free to shave off tissue from the cornea, reshaping it. A typical LASIK laser emits a 1.0-mm-diameter light amplification by stimulated emission of radiation beam with a wavelength of 193 nm. Each laser pulse lasts 15 ns and contains ane.0 mJ of light energy.
a. What is the ability of one laser pulse?
b. During the very cursory fourth dimension of the pulse, what is the intensity
of the light wave?
Sheh Lit C.
University of Washington
Problem 38
Using a dish-shaped mirror, a solar cooker concentrates the sun's free energy onto a pot for cooking. A cooker with a 1.5-k-bore dish focuses the dominicus's energy onto a pot with a diameter of 25 cm. Given that the intensity of sunlight is most 1000 West/m2
a. How much solar ability does the dish capture?
b. What is the intensity at the base of the pot?
Sheh Lit C.
Academy of Washington
Problem 39
The world's virtually powerful laser is the LFEX light amplification by stimulated emission of radiation in Japan. It can produce a two petawatt $\left(two \times ten^{xv} \mathrm{W}\right)$ laser pulse that last for 1 ps. The laser is focused onto a small spot that is $xxx \mu \mathrm{chiliad}$ in bore. What is the lite intensity inside this spot?
Sheh Lit C.
University of Washington
Problem 40
What is the sound intensity level of a sound with an intensity of $iii.0 \times x^{-6} \mathrm{W} / \mathrm{m}^{2}$ ?
Sheh Lit C.
University of Washington
Problem 41
What is the sound intensity of a whisper at a altitude of two.0 m,
in W/m2? What is the respective sound intensity level in dB?
Sheh Lit C.
University of Washington
Problem 42
The record for the world's loudest burp is 109.ix dB, measured at a distance of 2.5 m from the burper. Assuming that this sound was emitted equally a spherical wave, what was the power emitted past the burper during his record burp?
Sheh Lit C.
University of Washington
Problem 43
The audio intensity from a jack hammer breaking concrete is two.0 W/m2 at a altitude of 2.0 chiliad from the signal of impact. This is sufficiently loud to cause permanent hearing damage if the operator doesn't wear ear protection. What are (a) the sound intensity and (b) the sound intensity level for a person watching from 50 m away?
Sheh Lit C.
University of Washington
Problem 44
A concert loudspeaker suspended high off the ground emits 35 West of sound power. A small microphone with a ane.0 cm2 area is 50 yard from the speaker. What are (a) the audio intensity and (b) the sound intensity level at the position of the microphone?
Sheh Lit C.
Academy of Washington
Trouble 45
Ii The African cicada is the world's loudest insect, producing a sound intensity level of $107 \mathrm{dB}$ at a distance of $0.50 \mathrm{thou} .$ What is the intensity of its audio (in $\mathrm{W} / \mathrm{one thousand}^{2}$ ) as heard by someone standing $three.0 \mathrm{one thousand}$ away?
Sheh Lit C.
Academy of Washington
Trouble 46
From a distance of iv.0 one thousand, a eyewitness listens to a jackhammer breaking concrete. How far would he need to move from the jackhammer so that its perceived loudness decreases by a factor of 8?
Sheh Lit C.
Academy of Washington
Trouble 47
A stone band playing an outdoor concert produces sound at 120 dB 5.0 m abroad from their single working loudspeaker. What is the sound intensity level 35 g from the speaker?
Sheh Lit C.
University of Washington
Trouble 48
Your ears are sensitive to differences in pitch, but they are not very sensitive to differences in intensity. Yous are not capable of detecting a difference in sound intensity level of less than i dB. By what gene does the sound intensity increase if the sound intensity level increases from 60 dB to 61 dB?
Sheh Lit C.
Academy of Washington
Problem 49
30 seconds of exposure to 115 dB sound tin can damage your hearing, but a much quieter 94 dB may begin to crusade damage after 1 hour of continuous exposure. Y'all are going to an outdoor concert, and you'll be continuing near a speaker that emits 50 Westward of acoustic ability equally a spherical wave. What minimum
distance should you be from the speaker to proceed the audio intensity level beneath 94 dB?
Sheh Lit C.
University of Washington
Problem 50
When you speak, your vox sounds 10 dB louder to someone continuing direct in front of you than to someone at the aforementioned distance but directly behind you. What is the ratio of the intensity of your voice for someone in front of you lot to the intensity for someone backside yous?
Sheh Lit C.
University of Washington
Problem 51
An opera singer in a convertible sings a note at 600 Hz while cruising down the highway at ninety km/h. What is the frequency heard by
a. A person standing beside the road in front of the car?
b. A person standing abreast the route backside the car?
Sheh Lit C.
University of Washington
Trouble 52
An osprey's call is a singled-out whistle at 2200 Hz. An osprey calls while diving at yous, to bulldoze y'all away from her nest. You hear the call at 2300 Hz. How fast is the osprey approaching?
Sheh Lit C.
Academy of Washington
Trouble 53
A whistle you employ to call your hunting dog has a frequency of 21 kHz, but your domestic dog is ignoring it. You suspect the whistle may not be working, but you can't hear sounds above 20 kHz. To exam it, you ask a friend to blow the whistle, and then you hop on your bicycle. In which direction should y'all ride (toward or away from your friend) and at what minimum speed to know if the whistle is working?
Sheh Lit C.
University of Washington
Problem 54
An echocardiogram uses 4.four MHz ultrasound to measure claret flow in the aorta. The blood is moving away from the probe at 1.four m/due south. What is the frequency shift of the reflected ultrasound?
Sheh Lit C.
University of Washington
Trouble 55
A friend of yours is loudly singing a single note at 400 Hz while driving toward you at 25.0 1000/s on a day when the speed of sound is 340 m/southward.
a. What frequency exercise y'all hear?
b. What frequency does your friend hear if y'all all of a sudden start
singing at 400 Hz?
Vishal Grand.
Numerade Educator
Trouble 56
The frequency of light emitted from hydrogen present in the Andromeda galaxy has been establish to be 0.ten% higher than that from hydrogen measured on earth. Is this milky way approaching or receding from the globe, and at what speed?
Sheh Lit C.
University of Washington
Trouble 57
A Doppler blood period unit emits ultrasound at 5.0 MHz. What is the frequency shift of the ultrasound reflected from blood moving in an artery at a speed of 0.xx yard/s?
Sheh Lit C.
University of Washington
Problem 58
A train whistle is heard at 300 Hz as the train approaches town. The train cuts its speed in half equally it nears the station, and the sound of the whistle is then 290 Hz. What is the speed of the train before and after slowing down?
Sheh Lit C.
University of Washington
Trouble 59
At the xviii km cruising altitude of Concorde, a rider aircraft that flew at twice the speed of sound, the temperature was -57°C. What was the Concorde's cruising speed?
Problem lx
A 2.0-m-long string is nether 20 North of tension. A pulse travels the length of the string in l ms. What is the mass of the string?
Sheh Lit C.
Academy of Washington
Problem 61
A female orb spider has a mass of 0.50 yard. She is suspended from a tree co-operative by a 1.1 m length of 0.0020-mm-diameter silk. Spider silk has a density of 1300 kg/m3 . If you tap the branch and send a vibration down the thread, how long does it take to attain the spider?
Sheh Lit C.
Academy of Washington
Problem 62
A spider spins a web with silk threads of density 1300 kg/m3 and diameter 3.0 mm. A typical tension in the radial threads of such a web is 7.0 mN. Suppose a wing hits this web. Which volition reach the spider kickoff: the very slight sound of the impact or the disturbance traveling along the radial thread of the web?
Sheh Lit C.
Academy of Washington
Problem 63
In 2003, an earthquake in Japan generated i.1 Hz waves that traveled outward at 7.0 km/due south. 200 km to the west, seismic instruments recorded a maximum acceleration of 0.25g along the east-west axis.
a. How much fourth dimension elapsed between the convulsion and the first
detection of the waves?
b. Was this a transverse or a longitudinal moving ridge?
c. What was the wavelength?
d. What was the maximum horizontal deportation of the
ground equally the moving ridge passed?
Sheh Lit C.
University of Washington
Problem 64
A coyote can locate a sound source with practiced accurateness past
comparison the arrival times of a sound wave at its two ears.
Suppose a coyote is listening to a bird whistling at yard Hz.
The bird is iii.0 g away, directly in front of the coyote's right
ear. The coyote's ears are 15 cm apart.
a. What is the difference in the inflow times of the audio at the
left ear and the right ear?
b. What is the ratio of this times difference to the flow of the
audio moving ridge?
Sheh Lit C.
University of Washington
Problem 65
A wave travels along a steel string with a speed of 22 thousand/s. At some signal along the string, its bore doubles. What is the speed of the wave in this thicker part?
Sheh Lit C.
University of Washington
Problem 66
The string in Figure P15.66 has a linear density of $7.ii \times 10^{-5} \mathrm{kg} / \mathrm{1000} .$ What is the speed of a wave on this string?
Sheh Lit C.
University of Washington
Problem 67
Low-frequency vertical oscillations are one possible cause of motion sickness, with 0.xxx Hz having the strongest effect. Your gunkhole is bobbing in place at but the correct frequency to cause y'all the maximum discomfort. The water wave that is bobbing the boat has crests that are 30 k autonomously.
a. What is the speed of the waves?
b. What will be the boat's vertical oscillation frequency if y'all drive
the boat at 5.0 m/due south in the management of the oncoming waves?
Sheh Lit C.
University of Washington
Problem 68
Figure P15.68 shows two snapshot graphs taken 10 ms apart, with the blue curve being the start snapshot. What are the (a) wavelength, (b) speed, (c) frequency, and (d) amplitude of this moving ridge?
Sheh Lit C.
Academy of Washington
Problem 69
The force per unit area in a sound wave in steel is given by $p(x, t)=p_{\text {atm }}+p_{0} \cos \left(2.4 x-\left(i.iv \times ten^{4}\correct) t\correct),$ where $p_{\text {atm }}$ is atmospheric pressure, $p_{0}$ is the aamplitude of the moving ridge, $x$ is in $\mathrm{chiliad}$, and $t$ in s. What are the speed and frequency of this wave?
Sheh Lit C.
University of Washington
Problem 70
A wave on a string is described past $y(x, t)=(iii.0 \mathrm{cm}) \times$ $\cos [2 \pi(x /(2.4 \mathrm{m})+t /(0.xx \mathrm{s}))] .$ where $x$ is in $\mathrm{thou}$ and $t$ in $\mathrm{s}$
a. In what direction is this wave traveling?
b. What are the moving ridge speed, frequency, and wavelength?
c. At $t=0.50 \mathrm{s},$ what is the displacement of the cord at $x=0.20 \mathrm{one thousand} ?$
Sheh Lit C.
University of Washington
Problem 71
Write the y-equation for a wave traveling in the negative ten-management with wavelength 50 cm, speed 4.0 m/south, and aamplitude five.0 cm
Sheh Lit C.
Academy of Washington
Problem 72
A point on a cord undergoes simple harmonic movement as a sinusoidal wave passes. When a sinusoidal wave with speed 24 m/due south, wavelength 30 cm, and amplitude of 1.0 cm passes, what is the maximum speed of a point on the string?
Sheh Lit C.
Academy of Washington
Problem 73
The threshold of hearing—the lowest-intensity audio a person tin can hear—depends on, amongst many factors, the frequency of the sound. During a hearing exam, the hearing specialist creates an audiogram, a graph of the patient's hearing threshold (in dB) versus sound frequency; thresholds in a higher place 20 dB signal hearing loss. For the audiogram shown in Figure P15.73, what is the ratio of the sound intensity 1in W/m2 two of the faintest sound the
patient can hear at 1 kHz to that of the faintest sound she can hear at 6 kHz?
Sheh Lit C.
University of Washington
Trouble 74
The total power consumption by all humans on world is approximately 1013 W. Let's compare this to the power of incoming solar radiation. The intensity of radiation from the sun at the top of the atmosphere is 1380 Westward/m2. The earth'south radius is six.37 * 106 m.
a. What is the total solar power received past the earth?
b. Past what gene does this exceed the total homo power
consumption?
Sheh Lit C.
Academy of Washington
Problem 75
A dark bluish cylindrical bottle is 22 cm high and has a diameter of seven.0 cm. Information technology is filled with water. The bottle absorbs sixty% of the calorie-free that shines on it as it lies on its side in the noonday lord's day, with intensity 1000 W/m2 By how much will the temperature of the water increase in v.0 min if at that place's negligible
heat loss to the surrounding air?
Sheh Lit C.
University of Washington
Problem 76
Assume that the opening of the ear canal has a diameter of seven.0 mm. For this trouble, you tin ignore whatever focusing of free energy into the opening past the pinna, the external folds of the ear.
a. How much sound power is "captured" past ane ear at 0 dB,
the threshold of hearing?
b. How much energy does i ear "capture" during 1 hour of
listening to a lecture delivered at a conversational volume of
60 dB?
Sheh Lit C.
University of Washington
Problem 77
The audio intensity $50 \mathrm{k}$ from a wailing tornado siren is $0.10 \mathrm{W} / \mathrm{m}^{2} .$ What is the sound intensity level $300 \mathrm{m}$ from the siren?
Sheh Lit C.
University of Washington
Trouble 78
One of the loudest sound generators always created is the Danley Sound Labs Matterhorn. When run at full power, the device uses an input power of 40,000 W. The output power registers 94 dB at 250 m. What is the efficiency of this device— that is, the ratio of output power to input power?
Sheh Lit C.
University of Washington
Problem 79
A harvest mouse can detect sounds beneath the threshold of human hearing, as tranquility as -10 dB. Suppose you are sitting in a field on a very repose day while a harvest mouse sits nearby. A very gentle breeze causes a leafage 1.v yard from your head to rustle, generating a faint sound right at the limit of your ability to hear information technology. The sound of the rustling leaf is besides right at the threshold of hearing of the harvest mouse. How far is the harvest mouse from the leaf?
Sheh Lit C.
University of Washington
Problem 80
A speaker at an open-air concert emits 600 W of sound power, radiated as in all directions.
a. What is the intensity of the sound v.0 chiliad from the speaker?
b. What audio intensity level would you feel there if
you lot did not have any protection for your ears?
c. Earplugs you lot can buy in the drugstore take a noise reduction
rating of 23 decibels. If you are wearing those earplugs but
your friend Phil is not, how far from the speaker should Phil
stand to feel the same loudness as you?
Sheh Lit C.
Academy of Washington
Trouble 81
A physics professor demonstrates the Doppler effect by tying a 600 Hz sound generator to a ane.0-m-long rope and whirling it around her head in a horizontal circle at 100 rpm. What are the highest and lowest frequencies heard by a student in the classroom? Assume the room temperature is xx°C.
Sheh Lit C.
University of Washington
Trouble 82
When the heart pumps blood into the aorta, the pressure
gradient—the difference between the claret pressure inside
the heart and the claret pressure in the artery—is an important
diagnostic measurement. A directly measurement of the pressure
slope is difficult, but an indirect decision can be made
by inferring the pressure divergence from a measurement of
velocity. Blood is essentially at rest in the middle; when it leaves
and enters the aorta, it speeds up significantly and—co-ordinate
to Bernoulli'southward equation—the force per unit area must subtract. A doc
using 2.5 MHz ultrasound measures a 6000 Hz frequency shift
equally the ultrasound reflects from claret ejected from the heart.
a. What is the speed of the blood in the aorta?
b. What is the difference in blood pressure between the within
of the heart and the aorta? Assume that the patient is lying
down and that in that location is no difference in top every bit the claret
moves from the middle into the aorta.
Sheh Lit C.
University of Washington
Problem 83
Equally discussed in the chapter, many species of bats discover flying insects past emitting pulses of ultrasound and listening for the reflections. This technique is chosen echolocation. Bats possess several adaptations that allow them to echolocate very effectively. 83. | Although we tin can't hear them, the ultrasonic pulses are very loud. In guild non to be deafened by the audio they emit, bats can temporarily plow off their hearing. Muscles in the ear cause
the bones in their middle ear to separate slightly, and so that they don't transmit vibrations to the inner ear. Afterward an ultrasound pulse ends, a bat can hear an repeat from an object a minimum of 1 m away. Approximately how much fourth dimension after a pulse is emitted is the bat ready to hear its repeat?
A. 0.5 ms B. 1 ms C. 3 ms D. half-dozen ms
Sheh Lit C.
University of Washington
Trouble 84
Bats are sensitive to very small changes in frequency of the reflected waves. What data does this allow them to determine about their prey?
A. Size B. Speed C. Altitude D. Species
Sheh Lit C.
University of Washington
Problem 85
Some bats take specially shaped noses that focus ultrasound echolocation pulses in the forward direction. Why is this useful?
A. Increasing intensity reduces the fourth dimension delay for a reflected
pulse.
B. The free energy of the pulse is concentrated in a smaller area,
and then the intensity is larger; reflected pulses will have a larger
intensity too.
C. Increasing intensity allows the bat to use a lower frequency
and withal have the same spatial resolution.
Sheh Lit C.
Academy of Washington
Trouble 86
Some bats utilize a sound pulse with a rapidly decreasing frequency. A decreasing-frequency pulse has
A. Decreasing wavelength.
B. Decreasing speed.
C. Increasing wavelength.
D. Increasing speed.
Sheh Lit C.
University of Washington
Source: https://www.numerade.com/books/chapter/traveling-waves-and-sound-2/
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