Gravitational acceleration vs. air resistance effects

Steps:

• Objects dropped from 200m; after 1s, height change is small (~5m on Earth, ~0.8m on Moon), so still ~200m above surface.
• Weight (mg) constant as height variation negligible; g ≈ constant for both.
• On Moon, no atmosphere, so no drag; acceleration remains constant at g_moon.
• On Earth, atmosphere causes drag force proportional to velocity squared; as speed increases over 1s, drag rises, reducing net acceleration (g - drag/m).

Why A is correct:

• Net acceleration decreases for Earth object due to increasing air resistance (Newton's second law: net force = mg - drag, drag ∝ v²).

Why the others are wrong:

• B: Ignores air resistance on Earth; acceleration not constant there.
• C: Moon acceleration constant, not decreasing; Earth's increases only without drag.
• D: Neither acceleration increases; Earth's decreases due to drag, Moon's constant.

Final answer: A