Problem 17.1CYU: Check Your Understanding Imagine you observe two firework shells explode. You hear the explosion of... Problem 17.2CYU: Check Your Understanding Identify common sounds at the levels of 10 dB, 50 dB, and 100 dB. Problem 17.3CYU: Check Your Understanding Describe how amplitude is related to the loudness of a sound. Problem 17.4CYU: Check Your Understanding If you walk around two speakers playing music, how come you do not notice... Problem 17.5CYU: Check Your Understanding Describe how noise-canceling headphones differ from standard headphones... Problem 17.6CYU: Check Your Understanding How is it possible to use a standing wave’s node and antinode to determine... Problem 17.7CYU: Check Your Understanding You observe two musical instruments that you cannot identify. One plays... Problem 17.8CYU: Check Your Understanding What would happen if more than two frequencies interacted? Consider three... Problem 17.9CYU: Check Your Understanding Describe a situation in your life when you might rely on the Doppler shift... Problem 1CQ: What is the difference between sound and hearing? Problem 2CQ: You will learn that light is an electromagnetic wave that can travel through a vacuum. Can sound... Problem 3CQ: Sound waves can be modeled as a change in pressure. Why is the change in pressure used and not the... Problem 4CQ: How do sound vibrations of atoms differ from thermal motion? Problem 5CQ: When sound passes from one medium to another where its propagation speed is different, does its... Problem 6CQ: A popular party trick is to inhale helium and speak in a high-frequency, funny voice. Explain this... Problem 7CQ: You may have used a sonic range finder in lab to measure the distance of an object using a clicking... Problem 8CQ: The sonic range finder discussed in the preceding question often needs to be calibrated. During the... Problem 9CQ: Six members of a synchronized swim team wear earplugs to protect themselves against water pressure... Problem 10CQ: A community is concerned about a plan to bring train service to their downtown from the town’s... Problem 11CQ: You are given two wind instruments of identical length. One is open at both ends, whereas the other... Problem 12CQ: What is the difference between an overtone and a harmonic? Are all harmonics overtones? Are all... Problem 13CQ: Two identical columns, open at both ends, are in separate rooms. In room A, the temperature is T=20C... Problem 14CQ: How does an unamplified guitar produce sounds so much more intense than those of a plucked string... Problem 15CQ: Consider three pipes of the same length (L). Pipe A is open at both ends, pipe B is closed at both... Problem 16CQ: Pipe A has a length L and is open at both ends. Pipe B has a length L/2 and has one open end and one... Problem 17CQ: A string is tied between two lab posts a distance L apart. The tension in the string and the linear... Problem 18CQ: Two speakers are attached to variable-frequency signal generator. Speaker A produces a... Problem 19CQ: The label has been scratched off a tuning fork and you need to know its frequency. From its size,... Problem 20CQ: Referring to the preceding question, if you had only the 250-Hz fork, could you come up with a... Problem 21CQ: A “showy” custom-built car has two brass horns that are supposed to produce the same frequency but... Problem 22CQ: Is the Doppler shift real or just a sensory illusion? Problem 23CQ: Three stationary observers observe the Doppler shift from a source moving at a constant velocity.... Problem 24CQ: Shown below is a stationary source and moving observers. Describe the frequencies observed by the... Problem 25CQ: Prior to 1980, conventional radar was used by weather forecasters. In the 1960s, weather forecasters... Problem 26CQ: What is the difference between a sonic boom and a shock wave? Problem 27CQ: Due to efficiency considerations related to its bow wake, the supersonic transport aircraft must... Problem 28CQ: When you hear a sonic boom, you often cannot see the plane that made it. Why is that? Problem 29P: Consider a sound wave modeled with the equation s(x,t)=4.00nmcos(3.66m1x1256s1t) . What is the... Problem 30P: Consider a sound wave moving through the air modeled with the equation... Problem 31P: Consider a diagnostic ultrasound of frequency 5.00 MHz that is used to examine an irregularity in... Problem 32P: A sound wave is modeled as P=1.80Pasin(55.41m1x18,840s1t) . What is the maximum change in pressure,... Problem 33P: A sound wave is modeled with the wave function P=1.20Pasin(kx6.28104s1t) and the sound wave travels... Problem 34P: The displacement of the air molecules in sound wave is modeled with the wave function... Problem 35P: A speaker is placed at the opening of a long horizontal tube. The speaker oscillates at a frequency... Problem 36P: A 250-Hz tuning fork is struck and begins to vibrate. A sound-level meter is located 34.00 m away.... Problem 37P: A sound wave produced by an ultrasonic transducer, moving in air, is modeled with the wave equation... Problem 38P: Porpoises emit sound waves that they use for navigation. If the wavelength of the sound wave emitted... Problem 39P: Bats use sound waves to catch insects. Bats can detect frequencies up to 100 kHz. If the sound waves... Problem 40P: A bat sends of a sound wave 100 kHz and the sound waves travel through air at a speed of v=343 m/s.... Problem 41P: Consider the graph shown below of a compression wave. Shown are snapshots of the wave function for... Problem 42P: Consider the graph in the preceding problem of a compression wave. Shown are snapshots of the wave... Problem 43P: A guitar string oscillates at a frequency of 100 Hz and produces a sound wave. (a) What do you think... Problem 44P: When poked by a spear, an operatic soprano lets out a 1200-Hz shriek. What is its wavelength if the... Problem 45P: What frequency sound has a 0.10-m wavelength when the speed of sound is 340 m/s? Problem 46P: Calculate the speed of sound on a day when a 1500-Hz frequency has a wavelength of 0.221 m. Problem 47P: (a) What is the speed of sound in a medium where a 100-kHz frequency produces a 5.96-cm wavelength?... Problem 48P: Show that the speed of sound in 20.0°C air is 343 m/s, as claimed in the text. Problem 49P: Air temperature in the Sahara Desert can reach 56.0° C (about 134°F ). What is the speed of sound in... Problem 50P: Dolphins make sounds in air and water. What is the ratio of the wavelength of a sound in air to its... Problem 51P: A sonar echo returns to a submarine 1.20 s after being emitted. What is the distance to the object... Problem 52P: (a) If a submarine’s sonar can measure echo times with a precision of 0.0100 s, what is the smallest... Problem 53P: Ultrasonic sound waves are often used in methods of nondestructive testing. For example, this method... Problem 54P: A physicist at a fireworks display times the lag between seeing an explosion and hearing its sound,... Problem 55P: During a 4th of July celebration, an M80 firework explodes on the ground, producing a bright flash... Problem 56P: The density of a sample of water is =998.00kg/m3 and the bulk modulus is =2.15GPa . What is the... Problem 57P: Suppose a bat uses sound echoes to locate its insect prey, 3.00 m away. (See Figure 17.6.) (a)... Problem 58P: What is the intensity in watts per meter squared of a 85.0-dB sound? Problem 59P: The warning tag on a lawn mower states that it produces noise at a level of 91.0 dB. What is this in... Problem 60P: A sound wave traveling in air has a pressure amplitude of 0.5 Pa. What is the intensity of the wave? Problem 61P: What intensity level does the sound in the preceding problem correspond to? Problem 62P: What sound intensity level in dB is produced by earphones that create an intensity of 4.00102W/m2 ? Problem 63P: What is the decibel level of a sound that is twice as intense as a 90.0-dB sound? (b) What is the... Problem 64P: What is the intensity of a sound that has a level 7.00 dB lower than a 4.00109-W/m2 sound? (b) What... Problem 65P: People with good hearing can perceive sounds as low as -8.00 dB at a frequency of 3000 Hz. What is... Problem 66P: If a large housefly 3.0 m away from you makes a noise of 40.0 dB, what is the noise level of 1000... Problem 67P: Ten cars in a circle at a boom box competition produce a 120-dB sound intensity level at the center... Problem 68P: The amplitude of a sound wave is measured in terms of its maximum gauge pressure. By what factor... Problem 69P: If a sound intensity level of 0 dB at 1000 Hz corresponds to a maximum gauge pressure (sound... Problem 70P: An 8-hour exposure to a sound intensity level of 90.0 dB may cause hearing damage. What energy in... Problem 71P: Sound is more effectively transmitted into a stethoscope by direct contact rather than through the... Problem 72P: Loudspeakers can produce intense sounds with surprisingly small energy input in spite of their low... Problem 73P: The factor of 10-12 in the range of intensities to which the ear can respond, from threshold to that... Problem 74P: What are the closest frequencies to 500 Hz that an average person can clearly distinguish as being... Problem 75P: YY13Can you tell that your roommate turned up the sound on the TV if its average sound intensity... Problem 76P: If a woman needs an amplification of 5.0105 times the threshold intensity to enable her to hear at... Problem 77P: A person has a hearing threshold 10 dB above normal at 100 Hz and 50 dB above normal at 4000 Hz. How... Problem 78P: (a) What is the fundamental frequency of a 0.672-mlong tube, open at both ends, on a day when the... Problem 79P: What is the length of a tube that has a fundamental frequency of 176 Hz and a first overtone of 352... Problem 80P: The ear canal resonates like a tube closed at one end. (See [link]Figure 17_03_HumEar[/link].) If... Problem 81P: Calculate the first overtone in an ear canal, which resonates like a 2.40-cm-long tube closed at one... Problem 82P: A crude approximation of voice production is to consider the breathing passages and mouth to be a... Problem 83P: A 4.0-m-long pipe, open at one end and closed at one end, is in a room where the temperature is... Problem 84P: A 4.0-m-long pipe, open at both ends, is placed in a room where the temperature is T=25C . A speaker... Problem 85P: A nylon guitar string is fixed between two lab posts 2.00 m apart. The string has a linear mass... Problem 86P: A 512-Hz tuning fork is struck and placed next to a tube with a movable piston, creating a tube with... Problem 87P: Students in a physics lab are asked to find the length of an air column in a tube closed at one end... Problem 88P: If a wind instrument, such as a tuba, has a fundamental frequency of 32.0 Hz, what are its first... Problem 89P: What are the first three overtones of a bassoon that has a fundamental frequency of 90.0 Hz? It is... Problem 90P: How long must a flute be in order to have a fundamental frequency of 262 Hz (this frequency... Problem 91P: What length should an oboe have to produce a fundamental frequency of 110 Hz on a day when the speed... Problem 92P: (a) Find the length of an organ pipe closed at one end that produces a fundamental frequency of 256... Problem 93P: An organ pipe (L=3.00m) is closed at both ends. Compute the wavelengths and frequencies of the first... Problem 94P: An organ pipe (L=3.00m) is closed at one end. Compute the wavelengths and frequencies of the first... Problem 95P: A sound wave of a frequency of 2.00 kHz is produced by a string oscillating in the n=6 mode. The... Problem 96P: Consider the sound created by resonating the tube shown below. The air temperature is TC=30.00C .... Problem 97P: A student holds an 80.00-cm lab pole one quarter of the length from the end of the pole. The lab... Problem 98P: A string on the violin has a length of 24.00 cm and a mass of 0.860 g. The fundamental frequency of... Problem 99P: By what fraction will the frequencies produced by a wind instrument change when air temperature goes... Problem 100P: What beat frequencies are present: (a) If the musical notes A and C are played together (frequencies... Problem 101P: What beat frequencies result if a piano hammer hits three strings that emit frequencies of 127.8,... Problem 102P: A piano tuner hears a beat every 2.00 s when listening to a 264.0-Hz tuning fork and a single piano... Problem 103P: Two identical strings, of identical lengths of 2.00 m and linear mass density of =0.0065 kg/m, are... Problem 104P: A piano tuner uses a 512-Hz tuning fork to tune a piano. He strikes the fork and hits a key on the... Problem 105P: A string with a linear mass density of =0.0062 kg/m is stretched between two posts 1.30 m apart. The... Problem 106P: A car has two horns, one emitting a frequency of 199 Hz and the other emitting a frequency of 203... Problem 107P: The middle C hammer of a piano hits two strings, producing beats of 1.50 Hz. One of the strings is... Problem 108P: Two tuning forks having frequencies of 460 and 464 Hz are struck simultaneously. What average... Problem 109P: Twin jet engines on an airplane are producing an average sound frequency of 4100 Hz with a beat... Problem 110P: Three adjacent keys on a piano (F, F-sharp, and G) are struck simultaneously, producing frequencies... Problem 111P: (a) What frequency is received by a person watching an oncoming ambulance moving at 110 km/h and... Problem 112P: (a) At an air show a jet flies directly toward the stands at a speed of 1200 km/h, emitting a... Problem 113P: What frequency is received by a mouse just before being dispatched by a hawk flying at it at 25.0... Problem 114P: A spectator at a parade receives an 888-Hz tone from an oncoming trumpeter who is playing an 880-Hz... Problem 115P: A commuter train blows its 200-Hz horn as it approaches a crossing. The speed of sound is 335 m/s.... Problem 116P: Can you perceive the shift in frequency produced when you pull a tuning fork toward you at 10.0 m/s... Problem 117P: Two eagles fly directly toward one another, the first at 15.0 m/s and the second at 20.0 m/s. Both... Problem 118P: Student A runs down the hallway of the school at a speed of vo=5.00 m/s, carrying a ringing... Problem 119P: An ambulance with a siren (f=1.00kHz) blaring is approaching an accident scene. The ambulance is... Problem 120P: The frequency of the siren of an ambulance is 900 Hz and is approaching you. You are standing on a... Problem 121P: What is the minimum speed at which a source must travel toward you for you to be able to hear that... Problem 122P: An airplane is flying at Mach 1.50 at an altitude of 7500.00 meters, where the speed of sound is... Problem 123P: A jet flying at an altitude of 8.50 km has a speed of Mach 2.00, where the speed of sound is... Problem 124P: The shock wave off the front of a fighter jet has an angle of =70.00 . The jet is flying at 1200... Problem 125P: A plane is flying at Mach 1.2, and an observer on the ground hears the sonic boom 15.00 seconds... Problem 126P: A bullet is fired and moves at a speed of 1342 mph. Assume the speed of sound is v=340.00 m/s. What... Problem 127P: A speaker is placed at the opening of a long horizontal tube. The speaker oscillates at a frequency... Problem 128P: An airplane moves at Mach 1.2 and produces a shock wave. (a) What is the speed of the plane in... Problem 129AP: A 0.80-m-long tube is opened at both ends. The air temperature is 26°C. The air in the tube is... Problem 130AP: A tube filled with water has a valve at the bottom to allow the water to flow out of the tube. As... Problem 131AP: Consider the following figure. The length of the string between the string vibrator and the pulley... Problem 132AP: Early Doppler shift experiments were conducted using a band playing music on a train. A trumpet... Problem 133AP: Two cars move toward one another, both sounding their horns (fs=800Hz) . Car A is moving at 65 mph... Problem 134AP: Student A runs after Student B. Student A carries a tuning fork ringing at 1024 Hz, and student B... Problem 135AP: Suppose that the sound level from a source is 75 dB and then drops to 52 dB, with a frequency of 600... Problem 136AP: The Doppler shift for a Doppler radar is found by f=fR(1+vc1vc) , where fR is the frequency of the... Problem 137AP: A stationary observer hears a frequency of 1000.00 Hz as a source approaches and a frequency of... Problem 138AP: A flute plays a note with a frequency of 600 Hz. The flute can be modeled as a pipe open at both... Problem 139CP: Two sound speakers are separated by a distance d, each sounding a frequency f. An observer stands at... Problem 140CP: Consider the beats shown below. This is a graph of the gauge pressure versus time for the position... Problem 141CP: Two speakers producing the same frequency of sound are a distance of d apart. Consider an arc along... Problem 142CP: A string has a length of 1.5 m, a linear mass density =0.008 kg/m, , and a tension of 120 N. If the... Problem 143CP: A string (=0.006kgm,L=1.50m) is fixed at both ends and is under a tension of 155 N. It oscillates in... Problem 144CP: A string has a linear mass density µ, a length L, and a tension of FT, and oscillates in a mode n at... Problem 145CP: A string has a linear mass density =0.007 kg/m, a length L=0.70 m, a tension of FT=110 N, and... Problem 146CP: A speaker powered by a signal generator is used to study resonance in a tube. The signal generator... Problem 147CP: A string on the violin has a length of 23.00 cm and a mass of 0.900 grams. The tension in the string... format_list_bulleted
