Answer to Question 1
If the two moons were 180 degrees apart, then the moons' gravitational pulls on solid Earth would cancel each other and Earth would not be pulled more toward either moon. The forces exerted by the moons on the ocean surface would also partly counteract one another, although the ocean surface would still rise slightly toward each moon because the water on the side facing a moon is more strongly affected by that moon than it is by the moon on the opposite side of Earth.
If the moons were positioned 90 degrees apart the lunar forces would cancel each other out and Earth's oceans would only experience tides due to the sun.
Answer to Question 2
Since the source of the wave energy is the wind blowing across the ocean surface, the amount of wave motion decreases downward from the surface. When a wave passes, the rising-and-forward-moving part of the circular motion imparted to the water is closer to the surface than the sinking-and-backward-moving part of the motion. This results in a floating object moving forward a small amount in the direction of wave movement.
Annual net primary productivity on Earth.
The proboscis monkey demonstrates that large gut size contributes to a lower EQ.
How Orbital Eccentricity Changes the Amount of Solar Radiation Earth Receives
The rock cycle and the Earth’s physical environment
Earth’s Layered Structure
Formation of the Early Earth