1. A water wave has a frequency of 6 Hz and a wavelength of 3 m.
   1. what is the period (in seconds) of these waves?
   2. what is the wave velocity (in m/s)?
2. A 600.0 Hz sound has a velocity of 1087.0 ft/s in the air and a velocity of 4920.0 ft/s in water.
   1. what is the wavelength (in ft) of this sound in the air?
   2. what is the wavelength (in ft) of this sound in the water?
3. How much time (in second) will elapse between seeing and hearing an event that happens 400.0 meters from you? (Note: assume the velocity of sound in dry air @ 20 C and use velocity = 343 m/s)
4. A submarine sends a sonar signal, which returns from another ship 2.250 s later. How far away (in meter) is the other ship if the speed of sound in seawater is 1530.0 m/s?
5. What is the speed of sound, in ft/s, if the air temperature is: (a) 50.0C.
6. What is the speed of sound, in ft/s, if the air temperature is: (b) 100.0C