A person lying on an air mattress in the ocean rises and falls through one complete cycle every 3.00 seconds. The crests of the wave causing the motion are 20.9 m apart. Determine the frequency of the wave.

Answer: 0.33 Hz

Explanation: from the question, the distance between two successive crest is wavelength = 20.9m and the ocean rise and fall through one complete cycle every 3.00s which is the period. Hence T = period = 3.00s

Frequency = 1 / period

Frequency = 1/3 = 0.33 Hz