1. A bystander hears a siren vary in frequency from 580 Hz to 372 Hz as a re truck approaches, passes by, and moves away on a straight street. What is the speed of the truck? (Take the speed of sound in air to be 343 m/s.) m/s 2. A person standing a certain distance from sixteen identical loudspeakers is hearing a sound level intensity of 118 dB. What sound level intensity would this person hear if eight are turned off? dB 3. The figure shows a loudspeakerA and point C, where a listener is positioned. |AC| = 3.50 m and the angle a = 44 . A second loudspeaker B is located somewhere to the left of A. Both speakers vibrate in phase and are playing a 69.0 Hz tone. The speed of sound is 343 m/s. Excluding point (A), what is the third closest to speaker A that speaker B can be located, so that the listener hears maximum sound? m 4. Speakers A and B are vibrating in phase. They are directly facing each other, are 1.31 m apart, and are each playing a 715 Hz tone. The speed of sound is 345 m/s. On the line between the speakers there are points where minimum sound intensity occurs. What is the distance of the nearest point from speaker A? m :9 U 5. A string has a linear density of 7.00 X 10'3 kg/m and is under a tension of 285 N. The string is 2.4 m long, is xed at both ends, and is vibrating in the standing wave pattern shown below in the drawing. Determine the frequency of the traveling waves that make up the standing wave. Hz 6. A closed organ pipe has a fundamental frequency of 530 Hz (a C note) at 22 C. What is the fundamental frequency of the pipe when the temperature is 0C? Hz 7. What is the beat frequency heard when two organ pipes, each open at both ends, are sounded together if one pipe is 52 cm long and the other is 65 cm |ong?(The speed of sound is 340 m/s) Hz 8. A steel piano wire is 74.0 cm long and has a mass of 2.90 g. If the tension of the wire is 590 N, what is the fourth harmonic frequency? Hz 9. A pipe open only at one end has a fundamental frequency of 264 Hz. A second pipe, initially identical to the first pipe, is shortened by cutting off a portion of the open end. Now when both pipes vibrate at their fundamental frequencies, a beat frequency of 16 Hz is heard. How many centimeters were cut off the end of the second pipe? The speed of sound is 347 m/s. CITI 10. The figure shows two loudspeakers (A) and (B), and a point (C) where a listener is positioned. The speakers vibrate out of phase and are playing a 68.0 Hz tone. The speed of sound is 348 m/s. The listener at point (C) hears the third destructive interference (not counting the point at innity) at a distance 7.00 m as measured from speaker (A). What is the separation (d) between the two speakers? m