1. An observer stands between two sound sources. Source A is moving away from the observer, and source B is moving toward the observer. Both sources emit sound of the same frequency. If both sources are moving with a speed, vsound/6, what is the ratio of the frequencies detected by the observer?
2. A half-open pipe is constructed to produce a fundamental frequency of 250 Hz when the air temperature is 18 °C. It is used in an overheated building when the temperature is 38 °C. Neglecting thermal expansion in the pipe, what frequency will be heard?