The sound of normal breathing is not very loud, with an intensityof about 11 dB at a distance of 1 m away from the face of thebreather.
Note that in this problem sound intensity in decibels isdenoted beta; intensityin \rm W/m^{2} is denoted I.

Part A
Given that a person with normal hearing canbarely detect a sound with intensity of 1 dB at a frequency of 1kHz (the sensitivity of the human ear peaking near 1 kHz), how faraway could this person detect another person breathingnormally?
Express the distance D_detect inmeters.
D_detect =3.16 m
Correct
Part B
In general, if a sound has intensity ofbeta dB at 1 mfrom the source, at what distance d_0from the source would the decibel level decrease to 0 dB? Since thelimit of hearing is 1 dB this would mean you could no longer hearit.
Express the distance in terms ofbeta. Be carefulabout your signs!

Suppose water is leaking from a tank through a circular hole of area ah at its bottom. when water leaks through a hole, friction and contraction of the stream near the hole reduce the volume of water leaving the tank per second to cah 2gh , where c (0 < c < 1) is an empirical constant. a tank in the form of a right-circular cone standing on end, vertex down, is leaking water through a circular hole in its bottom. (assume the removed apex of the cone is of negligible height and volume.) (a) suppose the tank is 20 feet high and has radius 8 feet and the circular hole has radius 2 inches. the differential equation governing the height h in feet of water leaking from a tank after t seconds is dh dt = − 5 6h3/2 . if the height of the water is initially 8 feet, how long will it take the tank to empty? (round your answer to two decimal places.)

Ajoint produces movement when its angle decreases. which type of movement is it?

Ne way in which elements differ from each other is the structure of the electron cloud in each element's atoms. in an electron cloud, an electron that is farther away from the nucleus has