Concept explainers
Figure 17-32 shows the output from a pressure monitor mounted at a point along the path taken by a sound wave of a single frequency traveling at 343 m/s through air with a uniform density of 1.21 kg/m3. The vertical axis scale is set by ▵ps = 4.0 mPa. If the displacement function of the wave is s(x, t) = sm cos(kx − ωt), what are (a) sm, (b) k, and (c) ω? The air is then cooled so that its density is 1.35 kg/m3 and the speed of a sound wave through it is 320 m/s. The sound source again emits the sound wave at the same frequency and same pressure amplitude. What now are (d) sm, (e) k, and (f) ω?
Figure 17-32 Problem 14.
Want to see the full answer?
Check out a sample textbook solutionChapter 17 Solutions
Fundamentals of Physics, Volume 1, Chapter 1-20
Additional Science Textbook Solutions
Organic Chemistry
Cosmic Perspective Fundamentals
Campbell Biology (11th Edition)
Physics for Scientists and Engineers: A Strategic Approach, Vol. 1 (Chs 1-21) (4th Edition)
Chemistry: A Molecular Approach (4th Edition)
Human Anatomy & Physiology (2nd Edition)
- Two sinusoidal waves are moving through a medium in the positive x-direction, both having amplitudes of 7.00 cm, a wave number of k=3.00 m-1, an angular frequency of =2.50 s-1, and a period of 6.00 s, but one has a phase shift of an angle =12 rad. What is the height of the resultant wave at a time t=2.00 s and a position x=0.53 m?arrow_forwardThe figure shows the output from a pressure monitor mounted at a point along the path taken by a sound wave of a single frequency traveling at 346 m/s through air with a uniform density of 2.11 kg/m³. The vertical axis scale is set by Apg = 4.20 mPa. If the displacement function of the wave is written as s(x, t) = Sm cos(kx - wt), what are (a) sm, (b) k, and (c) w? The air is then cooled so that its density is 2.15 kg/m3 and the speed of a sound wave through it is 320 m/s. The sound source again emits the sound wave at the same frequency and same pressure amplitude. What now are (d) sm, (e) k, and (f) w? Ap (mPa) Aps 2.10 t (ms) (a) Number Units (b) Number Units (c) Number Units (d) Number Units (e) Number Units (f) Number Unitsarrow_forwardA sound wave propagating in air has a frequency of (7.86) kHz Calculate the change in wavelength when the wave, initially traveling in a region where T = (27.35}°C, enters a region where T = (5.99)°C.arrow_forward
- The area of a typical eardrum is about 5.0 × 10–5m2 . Calculate the sound power (the energy per second) incident on an eardrum at (a) the threshold of hearing and (b) the threshold of pain.arrow_forwardFor a 171Hz plane traveling wave in air with a sound pressure level of 40 dB re 20 pPa, find (a)the acoustic pressure amplitude, (b) the intensity, (c)the acoustic particle speed amplitude, (d) the acoustic density amplitude, (e) the particle displacement amplitudearrow_forwardSome studies suggest that the upper frequency limit of hearing is determined by the diameter of the eardrum. The wavelength of the sound wave and the diameter of the eardrum are approximately equal at this upper limit. If the relationship holds exactly, what is the diameter of the eardrum of a person capable of hearing 2.00 x 104 Hz? (Assume a body temperature of 37.0°C.)arrow_forward
- A sound wave arriving at your ear is transferred to the fluid in the cochlea. If the intensity in the fluid is 0.410 times that in air and the frequency is the same as for the wave in air, what will be the ratio of the pressure amplitude of the wave in air to that in the fluid? Approximate the fluid as having the same values of density and speed of sound as water. Speed of sound in dry air (20.0°C, 1.00 atm) is 343 m/s, density of dry air (at STP) is 1.29 kg/m3, density of water is 1000 kg/m3, and speed of sound in water is 1493 m/s.arrow_forwardA sound wave arriving at your ear is transferred to the fluid in the cochlea. If the intensity in the fluid is 0.430 times that in air and the frequency is the same as for the wave in air, what will be the ratio of the pressure amplitude of the wave in air to that in the fluid? Approximate the fluid as having the same values of density and speed of sound as water. Speed of sound in dry air (20.0°C, 1.00 atm) is 343 m/s, density of dry air (at STP) is 1.29 kg/m3, density of water is 1000 kg/m3, and speed of sound in water is 1493 m/s. Numeric Response: ______arrow_forwardProblem 7: An audio engineer takes decibel readings at distances of r1 = 11 m and r2 = 25 m from a concert stage speaker during a sound check. When he is r1 from the speaker, the engineer registers a decibel level of β1 = 103 dB on his loudness meter.Randomized Variables r1 = 11 mr2 = 25 mβ1 = 103 dBPart (a) What is the intensity of the sound, I1, in watts per square meter, that is measured by the loudness meter when the engineer is a distance of r1 from the speaker? Part (b) How much power P, in watts, is coming from the speaker during the sound check at distance r1? Part (c) Assuming that the speaker output does not change between the two measurements at r1 and r2, what sound intensity level β2, in decibels, will the loudness meter report when the engineer is at a distance r2 from the speaker?arrow_forward
- Figure 17-37 shows a transmitter and receiver of waves con- tained in a single instrument. It is used to measure the speed u of a target object (idealized as a flat plate) that is moving directly toward the unit, by analyzing the waves reflected from the target. What is u if the emitted frequency is 18.0 kHz and the detected frequency (of the returning waves) is 22.2 kHz?arrow_forwardConsider a composite wave formed by two plane waves with slightly different frequencies of 0, = 2.7 x 1012 rad/s and aw2 = 2.9 × 1012 rad/s and respective wavelengths A1 = 17.0 nm and 2 16.0 nm. Calculate the propagation velocity %D of the envelope wave and give your results in units of m/s with 1 digit precision, rounding off to one decimal place, i.e. the nearest tenth. (time budget 5min)arrow_forwardAssume that the displacement (s) of air is proportional to the pressure difference (Δp) created by a sound wave. Displacement(s) further depends on the speed of sound (v), the density of air (⍴) and the frequency (f). If Δp ~ 10Pa, v ~ 300 m/s, ⍴ ~ 1 kg / m3 and f ~ 1000 Hz, then s will be of the order of (take the multiplicative constant to be 1) 1) 1 mm 2) 10 mm 3) 1 / 10 mm 4) 3 / 100 mmarrow_forward
- University Physics Volume 1PhysicsISBN:9781938168277Author:William Moebs, Samuel J. Ling, Jeff SannyPublisher:OpenStax - Rice UniversityPrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning