Question

Define one metre, the S.I. unit of length. State its one multiple and one sub multiple.

Answer 1

One metre is defined as the distance travelled by light in vacuum in $\frac{1}{299,792,458}$ of a second.

The S.I. unit of length is metre and symbolised as m.
The multiple of metre in kilometre.
1 km = 1000 m
The submultiple of metre is centimetre.
$1cm={10}^{-2}m$