Question

question 7 (multiple choice worth 5 points)
(06.01 mc)
why does earth rotate?
○ because earth is formed from other planets collapsing due to gravity
○ because the matter in the nebula that formed earth was spinning
○ because earth forms more than 99% of the mass of the solar system
○ because the hydrogen atoms inside the nebula fused to form helium

Explanation:

To determine why Earth rotates, we analyze each option:

• Option 1: Earth wasn't formed from other planets collapsing; it formed from a nebula, so this is incorrect.
• Option 2: The nebula that formed the solar system (including Earth) had spinning matter. As the nebula collapsed, this angular momentum was conserved, leading to Earth's rotation. This is correct.
• Option 3: The Sun forms more than 99% of the solar system's mass, not Earth, so this is wrong.
• Option 4: Hydrogen fusion to helium occurs in the Sun, not in the nebula during Earth's formation, so this is incorrect.

Answer:

B. Because the matter in the nebula that formed Earth was spinning