Problem 4: You Problem 4 You stand at the top of a deep well. To determine the depth, D, of the well you drop a rock from the top of the well and listen for the : splash as the rock hits the water's surface. The sound of the splash arrives t: 3. 9 s after you drop the rock. The speed of sound in the well is vs : 330 III/S. D litl Part (:1) Enter the quadratic equation for the distance. D. in terms of the time. the acceleration due to gravity. and the speed of sound. Arrange the expression so that the coefcient of the D2 term is l. 0 2 Part (1)) Solve the quadratic equation for the depth of the well, D, and calculate it's value, in meters. D = Problem 6: The human ear can detect a minimum intensity of ID = [0'12 Wimz, which has a sound intensity of 0 dB. Randomized Variables ,8 = J 5 dB If the student hears a sound at J5 dB, what is the intensitl of the sound? I = Problem 7: A student hears a sound with a power of P = 49 uW. At their distance 'om the source, the sound has intensity1= 0.6-1 Wlmz. Part (2) Assuming the eardrum is circular, what is the radius of their eardrum, in meters? r1 = Part (b) Another student stands in the exact same location, but receives 20% more power from the same source. What is the radius of the second student's eardrums? r2 = Problem 8: Suppose an oncoming ambulance moving at 115 km/h emits a steady 820-Hz sound from its siren. Part (a) What frequency, in units of hertz, is received by a person watching the oncoming ambulance? The speed of sound on this day is 345 m/s. fobsi = Part (b) What frequency, in units of hertz, does she observe after the ambulance has passed? fobs,f = Problem 9: One day when the speed of sound in air is 343 m/s, a fire truck traveling at Vs = 22 m/s has a siren which produces a freq Randomized Variables Vs = 22 m/s f= 432 Hzvs = 22 m/s f= 432 Hz Part (a) What frequency, in units of hertz, does the driver of the truck hear? Fd= Part (b) What frequency, in units of hertz, does an observer hear when the truck is moving away? Fo= Problem 10: Consider a 0. 667-m long tube, open at both ends Part (a) What is the fundamental resonance frequency, in hertz, of the tube on a day when the speed of sound is 344 m/s? f1 = Part (b) What is the frequency, in hertz, of its second harmonic? f2 = Problem 11: What beat frequencies, in hertz, will be present in the following situations: Part (a) If the musical notes A and C are played together (frequencies of 220 and 264 Hz)? fb, A&C = Part (b) If D and F are played together (frequencies of 297 and 352 Hz)? fb, D&F = Part (c) An out of tune low C (128.5 Hz) and middle C (264 Hz)? fb, C3&C4 = Problem 12: The frequencies to which the ear can respond range over a factor of 10', from around 20 Hz to 20 KHz. Suppose the speedometer on your car measured speeds differing by the same factor of 10', and the greatest speed it reads is 90.0 mph. What would be the slowest nonzero speed it could read, in miles per hour? v = Problem 13: Ultrasound waves at intensities above 10# W/m can do serious damage to living tissues. If 10# W/m corresponds to 160 dB, what is the sound intensity level, in decibels, of ultrasound with intensity 10' W/m, used to pulverize tissue during surgery? B =