weight (w)=34π(8D3−d3)σg Buoyant force (Fb)=1×34π(8D3)⋅g For Just Float ⇒w=Fb ⇒(D3−d3)σ=D3⇒1−D3d3=σ1⇒1−σ1=(Dd)3⇒(σ−1σ)31=(dD)
A sphere of relative density σ and diameter D has concentric cavity of diameter d. The ratio of dD, if it just floats on water in a tank is :
Held on 9 Apr 2024 · Verified 6 Jul 2026.
(σ+2σ−2)1/3
(σ−1σ)1/3
(σσ−1)1/3
(σ−1σ+1)1/3
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