Relative density of an oil is `0.8`.Find the absolute density of oil in CGS and SI units.

Explanation

To find the absolute density of oil given its relative density, we can follow these steps:

### Step 1: Understand Relative Density
Relative density (also known as specific gravity) is the ratio of the density of a substance to the density of a reference substance, typically water. Since the relative density of oil is given as 0.8, it means that the density of oil is 0.8 times the density of water.

### Step 2: Density of Water
The density of water is approximately:
- In CGS units: \(1 \, \text{g/cm}^3\)
- In SI units: \(1000 \, \text{kg/m}^3\)

### Step 3: Calculate Absolute Density in CGS Units
Using the relative density, we can calculate the density of oil in CGS units:
\[ \text{Density of oil} = \text{Relative Density} \times \text{Density of Water} \]
\[ \text{Density of oil} = 0.8 \times 1 \, \text{g/cm}^3 = 0.8 \, \text{g/cm}^3 \]

### Step 4: Convert CGS Density to SI Units
To convert the density from CGS to SI units, we need to convert grams per cubic centimeter to kilograms per cubic meter. The conversion factor is:
\[ 1 \, \text{g/cm}^3 = 1000 \, \text{kg/m}^3 \]
Thus, we convert:
\[ 0.8 \, \text{g/cm}^3 = 0.8 \times 1000 \, \text{kg/m}^3 = 800 \, \text{kg/m}^3 \]

### Final Answers
- Absolute density of oil in CGS units: \(0.8 \, \text{g/cm}^3\)
- Absolute density of oil in SI units: \(800 \, \text{kg/m}^3\)

---