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
<em>Wave speed = 0.223 m/s</em>
F = G mM / r^2, where
<span>F = gravitational force between the earth and the moon, </span>
<span>G = Universal gravitational constant = 6.67 x 10^(-11) Nm^2/(kg)^2, </span>
<span>m = mass of the moon = 7.36 × 10^(22) kg </span>
<span>M = mass of the earth = 5.9742 × 10^(24) and </span>
<span>r = distance between the earth and the moon = 384,402 km </span>
<span>F </span>
<span>= 6.67 x 10^(-11) * (7.36 × 10^(22) * 5.9742 × 10^(24) / (384,402 )^2 </span>
<span>= 1.985 x 10^(26) N</span>
