Question

1. form hypothesis: do you think we always see the same side of the moon?
2. run gizmo: click play. the flag helps you notice how quickly the moon is rotating. click pause when the flag has rotated in a full circle, showing that the moon has rotated once.
3. observe: where does the flag point as the moon revolves around earth?
4. draw conclusions: do we always see the same side of the moon? how do you know?
5. observe:

a. how long did it take for the moon to go around earth?
b. how long did it take for the flag to rotate once in a full circle?

1. analyze: what do you notice about these two time intervals?
2. think and discuss: suppose the moon rotated on its axis just as quickly as earth. would we still always see the same side of the moon from earth? explain.

Explanation:

1. Form hypothesis: Based on prior knowledge, a hypothesis could be "Yes, we always see the same side of the Moon" (or no, if one has a different initial thought).
2. Run Gizmo: This is an experimental step where one observes the Moon's rotation (using the flag as a visual indicator).
3. Observe: As the Moon revolves around Earth, the flag (representing a fixed point on the Moon) should point towards Earth. This is because of the Moon's synchronous rotation.
4. Draw conclusions: Yes, we always see the same side of the Moon. We know this because the time it takes for the Moon to rotate (as indicated by the flag making a full - circle rotation) is the same as the time it takes for the Moon to revolve around Earth.
5. Observe:

• A. The time it takes for the Moon to go around Earth is about 27.3 days (sidereal month).
• B. The time it takes for the flag (representing the Moon's rotation) to rotate once in a full circle is also about 27.3 days.

1. Analyze: The two time intervals (Moon's rotation period and its revolution period around Earth) are equal.
2. Think and discuss: No, we would not. If the Moon rotated as quickly as Earth (Earth's rotation period is about 24 hours), while its revolution period around Earth is still about 27.3 days, the side of the Moon facing Earth would change over time. The synchronous rotation (equal rotation and revolution periods) is what causes us to always see the same side of the Moon.

Answer:

1. Hypothesis: Yes, we always see the same side of the Moon.
2. (Experimental step - no written answer required in this format)
3. The flag points towards Earth.
4. Yes, we always see the same side of the Moon. The time of Moon's rotation (flag rotation) is equal to its revolution time around Earth.

5.

• A. Approximately 27.3 days.
• B. Approximately 27.3 days.

1. The two time intervals (Moon's rotation and revolution) are equal.
2. No. If the Moon rotated as fast as Earth (24 - hour rotation) and still took 27.3 days to revolve around Earth, the side facing Earth would change.