Galileo's Equivalence Principle in Vacuum

Steps:

• Gravity on the Moon provides constant acceleration g to all objects, independent of mass.
• No atmosphere eliminates air resistance, so only gravitational force acts.
• Both spheres start from rest at identical height, experiencing same g.
• Time to fall h is t = sqrt(2h/g), equal for both.

Why D is correct:

• Newton's second law (F = mg) yields a = g, mass-independent, so identical motion.

Why the others are wrong:

• A: Acceleration is identical, not smaller for larger mass.
• B: Both hit simultaneously, not larger mass first.
• C: Acceleration is the same, not smaller for smaller mass.

Final answer: D