Further explanation
The length shows the distance between two points (symbol, L)
length measuring devices include a ruler, micrometer
The SI unit for length is m
The conversion of several units is:
1 km = 10³ m = 10⁵ cm
1 m = 10³ mm
38000 km = 3.8 x 10⁴ km = 3.8 x 10⁷ m
6.5 m = 6.5 x 10³ mm
4.3 ms = 4.3 x 10⁻³ s
0.02 km = 2 x 10⁻² x 10⁵ cm = 2 x 10³ cm