The density of water is approximately 1 g/cm^3. Which of the following objects will float on water?

• A. A block of wood with a density of 0.7 g/cm^3
• B. A piece of iron with a density of 7.9 g/cm^3
• C. A glass marble with a density of 2.5 g/cm^3
• D. A plastic cube with a density of 1.2 g/cm^3

Answer: (A)

Verified step by step guidance

1. Understand the principle of buoyancy: An object will float on water if its density is less than the density of water, and it will sink if its density is greater than that of water.
2. Recall that the density of water is given as 1 g/cm\^3, which serves as the reference point for comparing densities of other materials.
3. Compare the density of each object to the density of water: For each object, check if its density is less than 1 g/cm\^3 (float) or greater than 1 g/cm\^3 (sink).
4. Identify the object(s) with density less than 1 g/cm\^3. In this problem, the block of wood has a density of 0.7 g/cm\^3, which is less than water's density, so it will float.
5. Conclude that objects with densities greater than 1 g/cm\^3, such as the piece of iron, glass marble, and plastic cube, will sink in water.