### Step 4: Calculate Theoretical Density of the Composite
The theoretical density of the composite material (\(\rho_c\)) can be calculated using the weighted average of the densities based on the volume fractions:
\[
\rho_c = V_f \cdot \rho_f + V_m \cdot \rho_m
\]
### Example Calculation
Assume you have the following data:
- \(Wt_f = 60\%\) (fiber)
- \(Wt_m = 40\%\) (matrix)
- \(\rho_f = 1.5 \, \text{g/cm}^3\) (density of fiber)
- \(\rho_m = 1.0 \, \text{g/cm}^3\) (density of matrix)
The theoretical density of the composite material is \(1.25 \, \text{g/cm}^3\) based on the provided fiber and matrix densities and their weight percentages.