The Metric System FAQ

 1. Who started the metric system? The French introduced the metric system shortly after the French Revolution in the 1790s. 2. How far is a metre? A metre was initially defined a one ten millionth of the distance from the equator to the North Pole on a line running through Paris. It is currently defined as the length of the path travelled by light in a vacuum for a time of 1/299 792 458 th of a second. 3. Which are the most commonly used prefixes? Kilo − 1000 times the base unitcenti- 1/100th of the basic unitmilli- 1/1000th of the base unit 4. What is a litre? Think of a litre as a cube of side 10 cm. This gives an volume of 10 × 10 × 10 = 1000cm3 5. What is a tonne? A tonne is a mass of 1000 kg 6. How is temperature measured? There are two main units:Degrees Centigrade: 0oC = freezing point of water and 100oC = boiling point of waterDegrees Farenheit: 32oF= freezing point of water and 212oF= boiling point of waterTo convert oC to oF : multipy by 9/5 and add 32To convert oF to oC : subtract 32 and multipy by 5/9 7. What is a Hectare? A hectare is an area equivalent to a square of length 100m. i.e. 1 hectare = 100 × 100 = 10 000 m2 8. What is the difference between mass and weight? For mathematical purposes the mass and the weight are the same.