physic question

Question

 An acre is a common unit used to measure the area of a portion of land. An acre is equal to about 5000 m². What is this area in square kilometers (km²)?

Answer 1

This problem comes down to units and prefixes of units. All we need to do is convert m² to km². That prefix of "k" is kilo- thus its in reference to kilometer squared. For every 1000 meters we get a 1 kilometer, but for kilometer squared it's every 1,000,000 meter squared or 1000000 m² for every 1 kilometer squared. You have to square the conversion factor of 1 km/ 1000 m in order to properly get the right conversion factor.

Therefore we can make the conversation as such:

(5000 m²) • (1 km²/1000000 m²) = .005 km²