Which material will displace a volume of water equal to its own volume when fully submerged?

• A. A gas bubble released underwater
• B. A solid that is denser than water
• C. A liquid that mixes completely with water
• D. A solid that is less dense than water

Answer: (B)

Verified step by step guidance

1. Understand the principle of displacement: When an object is fully submerged in a fluid, it displaces a volume of fluid equal to the volume of the object itself. This is a direct consequence of Archimedes' principle.
2. Analyze each option in terms of displacement: - A gas bubble underwater will displace water equal to its volume, but since gases are compressible and less dense, the behavior can vary. - A liquid that mixes completely with water will not displace water in the traditional sense because it blends rather than pushing water aside. - A solid that is less dense than water will still displace water equal to its volume, but it will float rather than remain fully submerged. - A solid that is denser than water will sink and be fully submerged, displacing a volume of water exactly equal to its own volume.
3. Recall that displacement volume depends on the volume of the submerged object, not its density. However, whether the object remains fully submerged depends on its density relative to water.
4. Conclude that the material which will displace a volume of water equal to its own volume when fully submerged must be a solid denser than water, because it will sink and be completely underwater, pushing aside water equal to its volume.
5. Summarize: The key is full submersion and incompressibility. Only a solid denser than water will remain fully submerged and displace water equal to its own volume.