An iron nail sinks in water because it is denser than water.
Understanding Density and Sinking
When an object is placed in water, it either sinks or floats depending on its density compared to water. Density is defined as mass per unit volume. If an object's density is greater than the density of water, it will sink. If its density is less than water, it will float.
- Density: A measure of how much mass is packed into a given volume.
- Water Density: Water has a density of approximately 1 gram per cubic centimeter (1 g/cm³).
- Iron Density: The density of iron is approximately 7.87 g/cm³, which is much greater than that of water.
The Iron Nail Scenario
The provided reference states: "As the density of an iron nail is more than that of water, the nail sinks in water." This means that for the same amount of volume, an iron nail has more mass compared to water. As a result, it's denser and therefore sinks.
Why Density Matters
The key reason an iron nail sinks isn't about its weight, but its density. Consider these points:
- A large log of wood, which is much heavier than an iron nail, can float because its overall density is less than that of water.
- A small iron nail, even though it's light compared to the log, sinks because its density is much greater than that of water.
- The shape also plays a role, though secondary to density. If you were to flatten the same nail, it might still sink, but it would sink slower due to increased resistance. However, it will still be more dense than the water and it will still sink.
Practical Examples
Here are a few examples that demonstrate how density affects whether an object sinks or floats:
- Rock vs. Wood: Rocks typically sink due to high density, whereas wood often floats because it’s less dense than water.
- Steel Ship: Although steel is denser than water, a ship floats because its hull is filled with air, decreasing the overall density of the ship.
- Ice: Ice floats because it is less dense than liquid water, which is why icebergs float in the sea.
In Summary
The iron nail sinks because its density is greater than the density of water. This means that for a given volume, the iron nail packs more mass compared to water, causing it to sink.
