To convert millimeters (mm) to kilometers (km), we need to understand the relationship between these units. There are 1,000 millimeters in a meter and 1,000 meters in a kilometer. Therefore, there are 1,000,000 millimeters in a kilometer. We can use this conversion factor to convert 1500 mm to km.
Step 1: Conversion Factor
To convert from millimeters (mm) to kilometers (km), we use the conversion factor:
\[
1 \text{ km} = 1,000,000 \text{ mm}
\]
Thus, the conversion factor from mm to km is:
\[
\text{mm to km} = \frac{1}{1,000,000}
\]
Step 2: Apply the Conversion
Given \( 1500 \text{ mm} \), we can convert it to kilometers using the conversion factor:
\[
\text{km} = 1500 \text{ mm} \times \frac{1 \text{ km}}{1,000,000 \text{ mm}} = \frac{1500}{1,000,000} \text{ km}
\]