Two boys are whispering (one at a time) in the library. The radiated sound power from one boy's mouth is 1.2 × 10–9 W; and it spreads out uniformly in all directions. What is the minimum distance the boys must be away from the librarian so that she will not be able to hear them? The threshold of hearing for the librarian is 1.00 × 10–12 W/m2.
Two boys are whispering (one at a time) in the library. The radiated sound power from...
A woman stands a distance d from a loud motor that emits sound uniformly in all directions. The sound intensity at her position is an uncomfortable 3.2 *10-3 W/m2. At a position twice as far from the motor, calculate the following: (a) the sound intensity in W/m2 (b) the sound intensity level relative to the threshold of hearing
At a distance of 5.02 m from a siren, the sound intensity is 3.48 × 10-2 W/m2. Assuming that the siren radiates sound uniformly in all directions, find the total power radiated.
A woman stands a distance d from a loud motor that emits sound uniformly in all directions. The sound intensity at her position is an uncomfortable 4.0×10-3 W/m2. At a distance 3.2 times as far from the motor, what are (a) the sound intensity and (b) the sound intensity level relative to the threshold of hearing?
A woman stands a distance d from a loud motor that emits sound uniformly in all directions. The sound intensity at her position is an uncomfortable 3.4×10-3 W/m2. At a distance 2.5 times as far from the motor, what are (a) the sound intensity and (b) the sound intensity level relative to the threshold of hearing?
A 25 MW jet engine produces a sound level of 120 dB, the threshold of pain, at 100 m from the engine. (Recall that the threshold of human hearing is 1 x 10-12 W/m2.) (a) What portion of the jet engine power is lost in producing this sound? (b) You are at your quiet summer house (ambient sound level is 40 dB) and you can just hear the sound of the same jet engine at the airport. How far away...
x] Incorrect A woman stands a distance d from a loud motor that emits sound uniformly in all directions. The sound intensity at her position is an uncomfortable 2.8x10-3 W/m2. At a distance 1.9 times as far from the motor, what are (a) the sound intensity and (b) the sound intensity level relative to the threshold of hearing? .001 (a) Number Units X (b) Number Units
5. The threshold of human hearing at a frequency of 1.0 kHz is usually defined to be exactly 0 dB (for purposes of significant figures, consider this to be an exact, pure number). A research study shows that if exposed to 95 dB of a sound source for a long time, the threshold of hearing will shift upward to 32 dB. This accounts for why it is hard to hear normal conversations for some time after leaving a loud concert....
7. Suppose that a public-address system emits a 494 Hz sound uniformly in all directions. (a) If the air temperature is 25°C (sound travels at 346 m/s), what is the wavelength of this sound? (b) If the intensity at a location 22 m away from the sound source is 3x104 W/m2, what is the power of the sound coming from the speaker? Answer 8. Two boys are pulling a box across a horizontal floor. If Fi- 50 N, 30° N...
Two people are talking at a distance of 3 m from where you are and you measure the sound intensity as 9.3 × 10-7 W/m2. Another student is 9 m away from the talkers. What sound intensity, in 10-7 W/m2, does the other student measure? Assume that the sound spreads out uniformly and undergoes no significant reflections or absorption.
i have some physics questions. If an infant can scream at a sound level of 111.0-dB measured at a distance 11.0-cm from their mouth, how far away should a parent stand so that the child can be seen but not heard? (The threshold of hearing is 0-dB, or equivalently I0 = 10-12-Wm-2.) Assume spherical symmetry for the dispersion of the sound wave energy (this is of course a bad assumption). Answer km How much power is the child putting in...