Buoyant force depends on submerged volume Steps:

• Upthrust (buoyant force) equals weight of displaced water: ρ_water × g × submerged volume.
• Initially, block fully submerged with density equal to water, so upthrust = ρ_water × g × full volume.
• Held at fixed depth d (likely top at d, per common setup), so position fixed relative to surface.
• Changing y alters dimensions; without diagram, y's role (vertical/horizontal) ambiguous, affecting if submersion stays full.

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