Consider the reflection of plane waves from a bottom with the sound speed Profile 
The sound speed is continuous at the seabed (z D 0) and at z D 100 m, and the speed of sound in the water column (z < 0)=”” is=”” 1500=”” m/s.=””>
a. Determine the constants a and b.
b. What is the critical grazing angle for waves incident from the water column?
d. For a frequency of 100Hz, compute the phase of the reflection coefficient at
grazing angles of incidence 30ı; 40ı; 50ı; 60ı; 70ı; 80ı, and make a sketch of
the result.
