Question

How many centimetres make a kilometre?

Answer 1

Hint: Use the conversion formulas \[1km=1000m\] and \[1m=100cm\] for converting one unit system to another to get the number of centimetres in one kilometre. As \[1m=100cm\], convert \[1000m\] into centimetres by multiplying it by \[100\].

We have to find the number of centimetres that make one kilometre. We will use the conversion formulas for converting from one unit system to another one.
We know that \[1km=1000m\]. We now have to convert metres into centimetres. We know that \[1m=100cm\].
Thus, to convert \[1000m\] into centimetres, we will multiply it by \[100\].
So, we have \[1000m=1000\times 100cm={{10}^{5}}cm\].
Thus, we get \[1km=1000m={{10}^{5}}cm\].

Note: Centimetres, metres and kilometres represent the units of measuring distances or lengths. A unit of length refers to any arbitrarily chosen and accepted reference standard for measurement of length. The most commonly used unit of length is metres. It is also the base unit in the International System of Units. We can convert from one unit system to another one by appropriately multiplying or dividing the ratio of measurement of two units. To convert larger units into smaller units, we multiply the number of larger units by conversion factor for appropriate smaller units. To convert smaller units into larger units, we divide the number of smaller units by conversion factor for appropriate larger units. Larger unit systems like metres and kilometres are used to measure distance travelled by vehicles or distance between two cities, while smaller unit systems like centimetres are used to measure length of objects like tables and books. Some of the units of measurement of length also includes yard, mile, foot and inch.