Instructions: Please answer each of the following questions. You must show all work using correct formulas and units. You will not receive any points for a question if the answer is listed without the supporting work and verbal explanation. Round your answers to one to two decimal places ONLY, if applicable. 1. Explain what happens to the frequency and wavelength when: a sound source is approaching a stationary observer a sound source is receding from a stationary observer 2. What is the speed of sound in air with a temperature of 269 K? (10 points) 3. What is the speed of a wave with frequency of 170 Hz and a wavelength of 0.09 m? (10 points) 4. What is the maximum speed of a wave on a cable with length 50 m, mass of 200 kg, and a tension force of 1000 N applied to it? (10 points) 5. Using your answer from #4, what is the wavelength of the wave if it resonates with a frequency of 155 Hz? 6. Suppose that a 2 meter wave encounters an obstacle of width 20 cm. Will the diffraction of the wave be large or small? Explain your answer. 7.What is the frequency of a 0.0004 m ultrasonic wave passing through human tissue? Assume speed of sound in human tissue is 1500 m/s. 8. Explain how resonance can be used as a treatment in medical settings.