A Levels Physics (9702)•9702/11/M/J/19

Explanation
Archimedes' Principle for Floating Iceberg
Steps:
- Weight of iceberg equals buoyant force: ρ_i g (π r² H) = ρ_w g [π r² (H - h)].
- Cancel common terms: ρ_i H = ρ_w (H - h).
- Rearrange: ρ_w h = ρ_w H - ρ_i H.
- Solve: h = H (ρ_w - ρ_i)/ρ_w.
Why A is correct:
- Matches the equilibrium condition from Archimedes' principle, where h is the unsubmerged fraction proportional to the density difference.
Why the others are wrong:
- B: Represents submerged height fraction ρ_i/ρ_w, not above-water height.
- C: Exceeds H since ρ_w > ρ_i, impossible for floating object.
- D: Identical to B, incorrectly gives submerged fraction.
Final answer: A
Topic: Density and pressure
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