Question

a college student has been assigned to write captions for a new textbook on gravity and motion. this is one of the pictures from the textbook. which caption best describes the dotted - line arrow? the moon moves toward the sun due to gravity. the moon will move away from earth because of inertia. the moon would move in a circular path if there were no forces. the moon would not stay in orbit without the pull of earths gravity.

Explanation:

The solid arrow shows the moon's orbital direction, while the dotted arrow represents the path the moon would take if Earth's gravity (which keeps it in orbit) were removed. Inertia would make the moon move in a straight line tangent to its orbit, away from Earth's curved orbital path. Let's analyze each option:

1. The dotted arrow does not point toward the Sun, so this is incorrect.
2. The dotted arrow shows the straight-line path the moon would follow due to inertia if Earth's gravitational pull (which curves its path into orbit) was gone, so this matches.
3. Without forces, the moon would move in a straight line, not a circular path, so this is incorrect.
4. This describes the role of Earth's gravity, but the dotted arrow shows what happens without that pull, not the need for it, so this is incorrect.

Answer:

B. The moon will move away from Earth because of inertia.