Excellent question my son!

Wind speed is NOT the same as Wind force. In essence there is no such thing as "wind force".

Wind speed is referred to the time a "particle" of wind travels from one point to another. This is referred to as the wind speed and it's read in knots, miles, kilometres per time/hour, etc.

And of course force is the measurement of acceleration inversely proportional to mass. Therefore in our case we need to factor in the weight of the wind. But hang on! Wind does not have "mass". So how do we work out the force?

This is why a very smart guy called Admiral Beaufort created the Beaufort Scale.

en.wikipedia.org/wiki/Beaufort_scale

Quite simply, the BF scale is scientifically a measure of wind and it's independent of climate temperatures.

So really we should be measuring wind "forces" through the BF scale and say "today it's BF 4", which is more ideal to kite surfing in general as a BF of 4 or 5 considers most wind conditions suitable for kite surfing.

Never the less 10knots in Melbourne is also 10knots in the tropics, but scientifically it's categorised differently dependant on region. knots is knots no matter where you are in the world.

en.wikipedia.org/wiki/Wind#Wind_force_scale