Question

Two submarines are underwater and approaching each other head-on.Sub A has a speed of 4 m/s and sub B has aspeed of 14 m/s. Sub A sends out a1910 Hz sonar wave that travels at a speedof 1522 m/s.(a) What is the frequency of the sound detected by subB (to the nearest Hz)?Hz(b) Part of the sonar wave is reflected from B and returns to A.What frequency does A detect for this reflected wave (to thenearest Hz)?Hz

Answer 1

1933 Hz

1956 Hz

Step-by-step explanation:

`v_0` = Velocity of object

`v_s` = Velocity of source

v = Velocity of sound

From Doppler effect

`f=f'(v+v_0)/(v-v_s)\\\Rightarrow f=1910(1522+14)/(1522-4)\\\Rightarrow f=1932.64822134\ Hz=1933\ Hz`

The frequency of the sound detected by subB is 1933 Hz

`f=f'(v+v_0)/(v-v_s)\\\Rightarrow f=1932.64822134(1522+4)/(1522-14)\\\Rightarrow f=1955.7169\ Hz=1956\ Hz`

The frequency of the sound detected by subA is 1956 Hz