Two eagles fly directly toward one another, the first at 15.0 m/s and the second at 20.0 m/s. Both screech, the first one emitting a frequency of 3200 Hz and the second one emitting a frequency of 3800 Hz. What frequencies do they receive if the speed of sound is 330 m/s?

What frequency is received by a mouse just before being dispatched by a hawk flying at it at 25.0 m/s and emitting a screech of frequency 3500 Hz? Take the speed of sound to be 331 m/s.

A cable with a linear density of =0.2 kg/m is hung from telephone poles. The tension in the cable is 500.00 N. The distance between poles is 20 meters. The wind blows across the line, causing the cable resonate. A standing waves pattern is produced that has 4.5 wavelengths between the two poles. The air temperature is T=20C . What are the frequency and wavelength of the hum?

(II) If two firecrackers produce a combined sound level of85 dB when fired simultaneously at a certain place, whatwill be the sound level if only one is exploded? [Hint: Addintensities, not dBs.]

(II) When you slosh the water back and forth in a tub at just the right frequency, the water alternately rises and falls at each end, remaining relatively calm at the center. Suppose the frequency to produce such a standing wave in a 75-cm-wide tub is 0.85 Hz. What is the speed of thewater wave?

(II) Two automobiles are equipped with the same singlefrequency horn. When one is at rest and the other is moving toward the first at 18m/s the driver at rest hears a beat frequency of 4.5 Hz. What is the frequency the horns emit? Assume T = 20°C

(III) A police car sounding a siren with a frequency of 1580 Hz is traveling at 1280 km/h (a) What frequencies does an observer standing next to the road hear as the car approaches and as it recedes? (b) What frequencies areheard in a car traveling at 90.0 km/h in the opposite direction before and after passing the police car? (c) The police car passes a car traveling in the same direction at 80.0 km/h What two frequencies are heard in this car?

The frequency of whistle by a moving train and the frequency heard by a (c) stationary observer are 520 Hz and 460 Hz respectively. If the speed of sound in the air is 343 m s', calculate the speed of the train.

(II) Two piano strings are supposed to be vibrating at 220 Hz, but a piano tuner hears three beats every 2.5 s when they are played together. (a) If one is vibrating at 220.0 Hz, what must be the frequency of the other (is there only one answer)? (b) By how much (in percent) must the tension beincreased or decreased to bring them in tune?