Answer:
10 Hz.
Explanation:
v = Speed of sound in water = 1520 m/s
[tex]v_s[/tex]= Speed of dolphin = 7.2 m/s
[tex]f_s[/tex]= Frequency transmitted = 2210 Hz
Doppler effect
[tex]f=\frac{v}{v+v_s}f_s\\\Rightarrow f=\frac{1520}{1520+7.2}2210\\\Rightarrow f=2199.58\ Hz[/tex]
[tex]f_s-f=2210-2200 = 10 Hz[/tex]
∴ Difference (in Hz) between this frequency and the number of clicks per second actually emitted by the dolphin is 10 Hz.