A submarine (sub A) travels through water at a speed of 10.00m/s, emitting a sonar wave at a frequency of 1500 Hz. Bulk modulus of this sea water is 2.00 x 10^9 N/m^2 and density of this sea water is 1.03 g/cm^3. A second submarine (sub B) is located such that both submarines are traveling directly toward one another. The second submarine is moving at 12.00m/s.

(a) find the sound velocity in this water

(b) what frequency is detected by an observer, sub B, when they approach each other?

(c) what frequency is detected by an observer, sub B, when they pass each other and subs reced from each other?

(d) what is the frequency when the subs are approaching each other, some of the sound from sub A will reflect from sub B and return to sub A?