Why Is the Moon in a Synchronous Orbit Around Earth

question 33

Multiple Choice

Why is the Moon in a synchronous orbit around Earth, always keeping the same face toward Earth?

• A) There is a strong magnetic attraction between the two bodies that keeps the Moon turned toward Earth.
• B) The Moon must rotate on its axis at the same rate it orbits Earth to conserve angular momentum.
• C) As the Moon rotates, friction between the Moon's large liquid interior and its mantle has slowed the rate of rotation until it just matches the orbital rate. Over time it will slow further, and then the Moon will no longer be in a synchronous orbit.
• D) When the Moon was molten and experienced chemical differentiation, the gravitational pull of Earth caused large tides. The friction created as Earth's gravity attempted to keep the high tide bulge pointed toward Earth resulted in the Moon's rotation being slowed, causing it always to face Earth.

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Definitions:

Change in Demand

A shift in the demand curve, due either to changes in consumer preferences, income levels, prices of related goods, or other factors, affecting the quantity demanded at any given price.

Quantity Demanded

The total amount of a good or service that consumers are willing and able to purchase at a given price level, within a specific time frame.

Law of Supply

An economic principle stating that as the price of a good or service increases, the quantity supplied of that good or service also increases, and vice versa, all else being equal.

Law of Demand

A principle that describes the inverse relationship between the price of a good or service and the quantity demanded by consumers.