According to Newton's law of gravity, the Moon's gravitational pull produces how many tidal bulges (and thus high tides) on Earth at any given time?

• A. Four high tides (two pairs of tidal bulges)
• B. Two high tides (two tidal bulges on opposite sides of Earth)
• C. One high tide (one tidal bulge)
• D. Three high tides equally spaced around Earth

Answer: (B)

Verified step by step guidance

1. Recall that the Moon's gravitational force causes the water on Earth to experience a differential pull, leading to tidal bulges.
2. Understand that there are two tidal bulges formed: one on the side of Earth facing the Moon where the gravitational pull is strongest, and one on the opposite side where the inertia of the water causes a bulge.
3. Recognize that these two bulges correspond to two high tides on Earth at any given time.
4. Note that as Earth rotates, locations on its surface pass through these bulges, experiencing high tides twice each day.
5. Conclude that according to Newton's law of gravity, the Moon produces two tidal bulges, resulting in two high tides on Earth at any given time.