Final answer:
The correct answer is B) 2 conversion factors. We can create two conversion factors from the relation 1000 m = 1 km, one for converting meters to kilometers and another for converting kilometers to meters.
Step-by-step explanation:
If we know that 1000 meters (m) equals 1 kilometer (km), we can create two conversion factors to relate these units. One conversion factor would be 1 km / 1000 m, which would be used when converting from meters to kilometers. The other conversion factor would be 1000 m / 1 km, used to convert from kilometers to meters. Thus, we can derive two conversion factors based on the relationship between meters and kilometers.
To convert larger units to smaller units, such as kilometers to meters, we multiply by the conversion factor. For example, 5 kilometers can be converted to meters by multiplying 5 km by 1000 m / 1 km to get 5000 meters. Conversely, to convert smaller units to larger ones, like meters to kilometers, we use the inverse conversion factor. For instance, converting 400 meters to kilometers involves dividing 400 m by 1000 m / 1 km, thus obtaining 0.4 kilometers.