Archimedes' Principle for Floating Objects

Steps:

• Calculate ball's density: ρ_ball = mass / volume = 0.5 kg / 1.3 × 10^{-3} m³ ≈ 385 kg m^{-3}.
• For equilibrium, weight equals upthrust: mg = ρ_water × V_submerged × g, so V_submerged / V_total = ρ_ball / ρ_water.
• Fraction submerged = 385 / 1000 = 0.385 (38.5%).
• Fraction above water = 1 - 0.385 = 0.615 (61.5% ≈ 62%).

Why C is correct:

• 62% matches the unsubmerged volume fraction from Archimedes' principle, where buoyant force equals weight for floating equilibrium.

Why the others are wrong:

• A: 3% confuses unsubmerged with a tiny error in density calculation.
• B: 38% is the submerged fraction, not above water.
• D: 96% inverts the submerged fraction incorrectly.

Final answer: C