unit+8+2015

=Waves and the Doppler Effect=











media type="youtube" key="h4OnBYrbCjY" width="560" height="315"

__**PRACTICE TEST**__

1) What are harmonics and how are they related to the fundamental frequency? 2) What are nodes and antinodes? How can you use number of each to determine which harmonic is currently present? 3) How are transverse and longitudinal waves similiar? How are they different? 4) Graph a longitudinal wave in the same way you would graph tranverse waves. Label the points of compression and rarefaction. 5) What is interference and describe the two different types. 6) How do noise canceling headphones work? 7) What are beats and how do you determine the frequency of the beats? 8) Why do we only hear the moments of "positive" amplitude for longitudinal waves? (refer to question 4) 9) Given the size of a sound (resonant) chamber, how can you determine all possible frequencies that could be produced from those confined spaces? 10) How do brass musical instruments (tuba, trumpet, trombone, etc) create the different musical notes? Explain the concept of octaves and connect it to the idea of whole number waves, standing waves, and confined spaces.

11) Imagine a long, straight brass horn 5 meters long (RICOLLA!). What are the only frequencies that this horn can produce? Provide your answer in the form of an equation.

12) Sound wave A has an amplitude of 3 meters and a period of 3 seconds. Sound wave B has an amplitude of 4 meters but is one half the frequency. Graph the superposition of these two waves and find the beat frequency, amplitude, and wavelength of the resultant.

13) The speed of sound through air is 340 m/s and the speed of sound through helium is 1007 m/s. What is the apparent shift in frequencies when you speak through helium? (provide a conversion factor as your answer). Why does your voice gradually drop in frequency instead of shifting immediately back down?

14) Blue light has a frequency of approximately 650 THz (teraHertz) and, surprisingly, moves at the speed of light. What is the wavelength for this blue light wave?



media type="youtube" key="jEEytfWp9Q0" width="560" height="315"

media type="youtube" key="h2Th23BeUv8" width="560" height="315"