1. What is Fixed Relative Density?

Fixed Relative Density (RD) is a dimensionless quantity that represents the ratio of the density of a substance to the density of a reference material (water at 4°C, which has a density of 1000 kg/m³). It provides a standardized measure for comparing material densities.

2. How Does the Calculator Work?

The calculator uses the Fixed Relative Density formula:

Where:

• \( RD \) — Fixed Relative Density (dimensionless)
• \( Density \) — Material density in kg/m³
• 1000 — Reference density of water at 4°C (kg/m³)

Explanation: The calculation normalizes any material's density against the standard density of water, providing a relative measure that eliminates units and facilitates comparison between different materials.

3. Importance of Relative Density Calculation

Details: Fixed Relative Density is crucial in various scientific and engineering applications, including material science, fluid mechanics, geology, and quality control processes where density comparisons are essential.

4. Using the Calculator

Tips: Enter the material density in kg/m³. The value must be valid (density > 0). The calculator will automatically compute the fixed relative density relative to water.

5. Frequently Asked Questions (FAQ)

Q1: Why use water as the reference for relative density?
A: Water is used as the standard reference because it's abundant, well-studied, and has a consistent density of 1000 kg/m³ at 4°C, making it an ideal benchmark for comparison.

Q2: What are typical relative density values?
A: Most materials have relative density values greater than 1 (they sink in water). Values less than 1 indicate materials that float in water.

Q3: How does temperature affect relative density calculations?
A: Since both the sample and reference densities can change with temperature, measurements should ideally be made at standard conditions (4°C for water reference) for accurate comparisons.

Q4: Can this calculator be used for gases?
A: Yes, but note that gas densities are typically much lower than water, resulting in very small relative density values (much less than 1).

Q5: What's the difference between relative density and specific gravity?
A: Relative density and specific gravity are essentially the same concept - both represent the ratio of a material's density to that of a reference substance (usually water).