Waves & Sound 1. Calculate the speed of sound if the air temperature is 27C. 2. A plane is flying at Mach 3 through air that has a temperature of 36C. 3. Standing waves are produced in a string by two waves traveling in opposite directions at 6.0 m/s. The distance between the second and sixth node is 80 cm. Determine the wavelength and frequency of the original waves. 4. A closed tube 50.0 cm long resonates at its shortest resonant length (fundamental frequency) with a tuning fork at an air temperature of 25C. (at one end) a) What is the wavelength? b) What is the frequency of the tuning fork? c) What is the frequency of the third harmonic? 5. A 250 Hz tuning fork is sounded along with a note of unknown frequency. 3 beats per second are heard. What are the possible frequencies of the unknown