Concept explainers
Energy delivered to the ear. Sound is detected when a sound wave causes the tympanic membrane (the eardrum) to vibrate. (See Figure 12.29.) Typically, the diameter of this membrane is about 8.4 mm in humans. (a) How much energy is delivered to the eardrum each second when someone whispers (20 dB) a secret in your ear? (b) To comprehend how sensitive the ear is to very small amounts of energy, calculate how fast a typical 2.0 mg mosquito would have to fly (in mm/s) to have this amount of kinetic energy.
Want to see the full answer?
Check out a sample textbook solutionChapter 12 Solutions
College Physics (10th Edition)
Additional Science Textbook Solutions
Conceptual Physics (12th Edition)
Essential University Physics: Volume 1 (3rd Edition)
The Cosmic Perspective
Life in the Universe (4th Edition)
College Physics: A Strategic Approach (3rd Edition)
Essential University Physics (3rd Edition)
- As you zip through space in your PPS (personal propulsion suit), your pulse rate as you count it is 117 bpm (beats per minute). This high pulse rate serves as objective evidence of your excitement. However, an observer on the Moon, an expert in pulse rate telemetry, measures your pulse rate as slower. In fact, she detects only 0.525 times the rate you count and claims that you must be pretty calm in spite of everything that is going on. How fast are you moving with respect to the Moon? m/s speed relative to the Moon:arrow_forwardTwo students hear the same sound and their eardrums receive the same power from the sound wave. The sound intensity at the eardrums of the first student is 0.93 W/m2, while at the eardrums of the second student the sound intensity is 1.16 times greater. If the diameter of the second student’s eardrum is 1.1 cm, how much acoustic power, in microwatts, is striking each of his (and the other student’s) eardrums?arrow_forwardSound is detected when a sound wave causes the tympanic membrane (the ear drum) to vibrate. Typically, the diameter of this membrane is about 8.4 mm in humans. A) how much energy is delivered to the eardrum each second when someone whispers (20 dB) into your ear? B) to comprehend how sensitive the ear is to very small amounts of energy, calculate how fast a typical 2.0 mg mosquito would have to fly (in mm/s) to have this amount of kinetic energy.arrow_forward
- A sound wave with intensity 2 x 10 -3 W/m2 is perceived to be modestly loud. Your eardrum is 6 mm in diameter. How much energy will be transferred to your eardrum while listening to this sound for 1 minute?arrow_forwardEnergy Delivered to the Ear. Sound is detected when a sound wave causes the tympanic membrane (the eardrum) to vibrate. Typically, the diameter of this membrane is about 8.4 mm in humans. (a) How much energy is delivered to the eardrum each second when someone whispers (20 dB) a secret in your ear? (b) To comprehend how sensitive the ear is to very small amounts of energy, calculate how fast a typical 2.0 mg mosquito would have to fly (in mm/s) to have this amount of kinetic energy.arrow_forwardA particular person's eardrum is circular, with a diameter of 9.00 mm. (a)How much sound energy (in J) is delivered to an eardrum in one second, at the threshold of human hearing? (The threshold of human hearing is taken to be 1.00 ✕ 10−12 W/m2.) J (b)How much sound energy (in J) is delivered to an eardrum in one second, at the pain threshold for human hearing? (The pain threshold occurs at 1.00 W/m2, one trillion times as intense as the lowest audible level.) J (c)Assume that musicians onstage are exposed to sound that is 10 decibels below the human pain threshold. Over the course of a two-hour concert, how much sound energy (in J) does each ear absorb onstage? Jarrow_forward
- The speed of sound at room temperature (20°C) is 343 m/s. If the speed of sound in air increases about 0.60 m/s for every 1°C increase, what is the speed of sound when the temperature is 45°C? m/sarrow_forwardthe human ear tends to be most sensitive to sound frequencies of 3 khz. the sound intensity at this frequency is usually measured as 3x10-13 w/m2. how much energy is transported by this type of sound wave to the eardrum (surface area of about 50mm2 ) in 200msarrow_forwardWhat is the signal range for brain EEG recorded on the scalp? 10^1 - 10^3 V 10^-5 - 10^-3 V O 10^-5 - 10^-1 V O 10^-4 - 10^-2 Varrow_forward
- Sound waves travel at roughly 340 m/s at room temperature. The minimum hearing range of a human is 20Hz. a) What is the wavelength of this wave? b) Could this wavelength fit inside the dimensions of Room 411( room dimensions are roughly 11.5 m x 8.7 m)? Justify your answer with sound reasoning (pun intended :-))arrow_forwardRasim and Zhihan are experimenting to determine the speed of sound in m/s in air at 0°C. Assuming air to be made up of diatomic molecules with a molecular mass of 29 g/mol, what is the correct value they should expect for the speed of sound in m/s?arrow_forwardEver since seeing Figure 16.22 in the previous chapter, you have been fascinated with the hearing response in humans. You have set up an apparatus that allows you to determine your own threshold of hearing as a function of frequency. After performing the experiment and recording the results, you graph the results, which look like Figure P17.22. You are intrigued by the two dips in the curve at the right-hand side of the graph. You measure carefully and find that the minimum values of these dips occur at 3 800 Hz and 11 500 Hz. Performing some online research, you discover that the outer canal of the human ear can be modeled as an air column open at the outer end and closed at the inner end by the eardrum. You use this information to determine the length of the outer canal in your car. Figure P17.22arrow_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 LearningPhysics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
- Physics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningCollege PhysicsPhysicsISBN:9781285737027Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningCollege PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage Learning