What is the conversion factor between km/hr and m/s?

To convert ##(km.)/(hr.)## to ##m/(sec)##, one needs to multiply by ##5/18##.

##1## km/hr means ##1000## meters in ##3600## seconds or ##1000/3600=5/18## ##m/sec##.

Hence, if one has to convert ##(km.)/(hr.)## to ##m/(sec)##, one needs to multiply by ##5/18##.

For converting ##m/(sec)## to ##(km.)/(hr.)## one needs to divide by ##5/18## i.e. multiply by ##18/5##.