Buoyancy: fraction of a floating object submerged
A block of wood with density 600 kg/m³ floats in water (1000 kg/m³). What fraction of its volume is below the surface?
Answer B: explanation for every choice
A
0.4 is the fraction above the surface.
B
Correct. For a floating object, fraction submerged = ρobject/ρfluid = 600/1000 = 0.6.
C
Fully submerged and floating would mean the block's density equals water's.
D
This inverts the ratio. A fraction submerged cannot exceed 1.
TakeawayFraction submerged = ρobject/ρfluid.
Equations usedBuoyant force (Archimedes)Density and specific gravity
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