The caudal fin actuation of fish made of silicone can be explained by an added mass effect. As seen in the figures, the resonance frequency in water decreases in comparison to that in air.

(a) Explain the reason for the resonance frequency shift in terms of an added mass effect.

(b) If the silicone caudal fin is made of steel, does an added mass effect occur? Explain the reason why or why not.

00 8 9 Air/Tail Theoretical value air data Normalized Amplitude Ratio 2 0 02 4 6 8 10 Frequency (Hz)