Wave speed = (wavelength) x (frequency)
We know the wavelength, but we don't know the frequency. How can we find the frequency ? "Here frequency frequency."
We know the period, and frequency is just (1 / period). So . . .
Wave speed = (wavelength) / (period)
Wave speed = (2.1 meters) / (9.4 seconds)
Wave speed = (2.1 / 9.4) m/s
Wave speed = 0.223 m/s
