Part C Two powerful speakers, separated by 15.00 m. stand on the floor in front of the stage in a large amphitheater. An aisle perpendicular to the stage is directly in front of one of the speakers and extends 50.00 m to an exit door at the back of the amphitheater. The speed of sound in air is 344 m/s Suppose the coherent sound emitted from both speakers is a linear superposition of a 440.0 Hz tone and another tone with frequency. What is the smallest value of f so that minimal sound is heard at any point where the 440.0 Hz sound is minimal? Express your answer with the appropriate units. ? finValue Units Submit Request Answer Submit Request Answe Part D Two powerful speakers, separated by 15.00 m stand on the floor in front of the stage in a large amphitheater. An aisle perpendicular to the stage is directly in front of one of the speakers and extends 50.00 m to an exit door at the back of the amphitheater. The speed of sound in air is 344 m/s At how many additional points in the aisle is the 440.0 Hz tone present but the second tone is minimal? ΜΕ ΑΣΦ ? N= Submit Request Answer

A certain organ pipe, open at both ends, produces a fundamental frequency of 275 Hz in air. Part A If the pipe is filled with helium at the same temperature, what fundamental frequency fHe will it produce? Take the molar mass of air to be 28.8 g/mol and the molar mass of helium to be 4.00 g/mol. Express your answer in hertz. ► View Available Hint(s) fHe = 806 Hz Submit Previous Answers Correct Correct answer is shown. Your answer 805.9 Hz was either rounded differently or used a different number of significant figures than required for this part. Because helium is less dense than air and has a lower molar mass, sound waves propagate faster in helium than in air. Thus, the frequencies produced in the pipe when it is filled with helium are higher than those produced in the same pipe filled with air. Part B Now consider a pipe that is stopped (i.e., closed at one end) but still has a fundamental frequency of 275 Hz in air. How does your answer to Part A, ƒHe, change? ► View Available…

A pulsating sphere of radius a = 0.2 m radiates spherical waves in air at 3000 Hz and with intensity 80mW/m² at a distance 3.0 m from the surface of the sphere. The intensity at the surface of the sphere is? Select one: O a. Ob. 0.72 W/m² O C. 18 W/m² d. 32 mW/m² 80 mW/m² For the sphere in question 9 which of the following holds? a. Select one: O C. The acoustic power is equal to 9.05 W and independent of the distance from the centre of the sphere. b. The acoustic power is equal to 9.05 W and inversely proportional to the square of the distance from the centre of the sphere. The acoustic power is equal to 4.0 mW and independent of the distance from the centre of the sphere. d. The acoustic power is equal to 4.0 mW and inversely proportional to the square of the distance from the centre of the sphere.

Problem 2 Two speakers A and B, separated by a distance y = 2 meters, blast the same tone at f = 774 Hz. You walk along the line from B to towards C with a microphone. a) If you walk a positive distance x, what is the difference in the path length traveled by the sound coming from each speaker to you (since this is for any x, you can leave it in terms of arbitrary y for now). b) Assuming a speed of sound of 344 m/s, there are four finite distances T1, T2, T3, and ₁ at which you will hear constructive interference. What are their numerical values? c) How many locations are there with destructive interference? What are they? AD B ↑ 2.00 m d) There is a critical frequency fe below which you will not find any locations with constructive interference no matter how far you walk. What is this critical frequency? e) There is another critical frequency fa below which you won't find any locations with destructive interference. What is fa?