practice

  1. The graph below is a record of sea level heights recorded at Hanimaadhoo, Maldives (6° 46' N 73° 10' E) during the tsunami of 26 December 2004. The data were filtered to eliminate the normal tidal fluctuations, so what you are seeing is the increase in sea level due to the tsunami (Data Source: University of Hawaii Sea Level Center).


    [magnify]

    Natural phenomena are normally very noisy (in the statistical sense) but from 10:50 to 12:05 local time the changes in sea level at Hanimaadhoo were most nearly periodic. During this time interval determine the tsunami's mean …
    1. amplitude and
    2. period
    The speed of a tsunami varies with depth. In the open ocean they normally move as fast as a commercial jet airplane (about 250 m/s or 900 kph) but slow down to the speed of a car on a neighborhood street when they reach the shallow waters of the shore (about 15 m/s or 55 kph). Given these speeds, determine the mean wavelength of the segment of the tsunami that arrived in Hanimaadhoo between 10:50 and 12:05 when they were …
    1. near the shore and
    2. in deep water
    One final question.
    1. How would the amplitude of a tsunami near shore compare to the amplitude of the same wave in the open ocean? Explain your reasoning.
  2. Write something else.
  3. Write something different.
  4. Write something completely different.

numerical

  1. AM radio broadcasts in the US are allocated frequencies from 530 kHz to 1710 kHz. What range of wavelengths correspond to these frequencies? (All electromagnetic waves travel at the speed of light.)
  2. FM radio broadcasts in the US are allocated frequencies from 88 MHz to 108 MHz. What range of wavelengths correspond to these frequencies? (All electromagnetic waves travel at the speed of light.)
  3. Visible light ranges in wavelength from 400 nm (violet) to 700 nm (dull red). What is the corresponding range of frequencies?
  4. Each of the six strings on an acoustic guitar is 80 cm long and generates a wave that's twice the length of the string when picked or strummed. Determine the wave speed of each string given the following tuning.
    1. 082.41 Hz
    2. 110.00 Hz
    3. 146.83 Hz
    4. 196.00 Hz
    5. 246.94 Hz
    6. 329.63 Hz