A Levels Physics (9702)•9702/12/M/J/23

Explanation
Mass proportional to volume for same density cubes
Steps:
- Density ρ is identical for X and Y, so mass m = ρ × volume V.
- Volume of cube is side length cubed: V_X = x³, V_Y = y³.
- Given m_X = 2 m_Y, substitute: ρ x³ = 2 ρ y³.
- Simplify: x³ / y³ = 2, so (x/y)³ = 2, x/y = ∛2 ≈ 1.26.
Why A is correct:
- ∛2 equals 1.26 by the cube root definition, directly from the volume formula V = side³ for equal-density solids.
Why the others are wrong:
- B: 1.41 is √2, ratio for 2D areas, not 3D volumes.
- C: 2.00 assumes mass scales linearly with side, ignoring cubic volume.
- D: 8.00 is 2³, the volume ratio, not the side ratio.
Final answer: A
Topic: Density and pressure
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