Two boats- boats A and B are anchored a distance of 18 meters apart . The incoming water waves force the boat to oscillate up and down, making one complete cycle every 20 seconds. When boat A is at its peak, boat B is at its low point and there is a crest in between bthe two boats. Vertical distance between the boats is 12 meters. The wavelength is m, period is ___ s, frequency is ___ Hz, and the amplitude is ___m.