Question

I am completing a study guide, and was able to complete the first 2 pages. Any help on these questions?
You are driving south on a road at a speed of 21.3 m/s and you hear a siren from a police car at a frequency of 915 Hz, as the police car approaches you while driving north. If the police car is going at a speed of 32.4 m/s, and the speed of sound is 343 m/s, what frequency would the police man hear? A string, 0.528 m long and vibrating in its forth harmonic, excites an open-open pipe that is 0.310 m long into its third harmonic resonance. The speed of sound in air is 343 m/s. If the string has a mass of 4.50 grams for every meter, how much tension is in the string? A tuning fork with frequency 505 Hz is placed over a pipe that is open at one end and has an adjustable boundary at the other allowing this open/closed pipe to change its length. Knowing the speed of sound to be 341 m/s and that the pipe with length.169 m makes the first standing wave, to what distance should the boundary next be placed at to make a standing wave? Light of wavelength 591 nm shines on soap film (n-1.27) having air on both sides of it. What is the minimum thickness (in nm) of the film that will produce constructive reflection when the light hits it straight on?

Answer 1