very tricky question!

Dylan123

Question: If you have a kite with a projected area of 6.1m2 and a gust of wind hits the kite at 60mph or 80mph how many kg of pressure would this exert? The more wind exerted on the kite the harder it is to pull the safety. If there is 200kg of pressure it takes 7kg of pressure to pull the safety - how many kgs of pressure would it take to release the safety at 60-80mph?

Also wonder how it is possible to calculate as this when shape of the kite will depend on several factors:

(1) There are two 25m lines connected to the front and two at the back
(2) The lines at the back can be extended by approx 8cm (which has the same effect as an airplane wing )

The manufactures state the max wind speed is 30 knots of wind - i am wondering what will happen when the wind doubles or tripples in a gust?
The reason for the question is because the technology is relatively new (every year its updated) and peoples lives are in danger. Even a slight idea of the pressure we are dealing with would give me a good idea! many thanks i know its an awkward question. But this may of real help to people in the future

RoundTower

This isn't really a maths question, it's a question about a very specific branch of engineering.

Look at some of the replies on this page to see how complicated the calculations are: there are tables and tables for the pressure on different shapes of sail.

In general, however, the pressure varies with the square of the wind speed. If the wind blows twice as hard, there will be four times as much pressure.

This site gives a rough calculator for the pressure on a sail (motivated by predicting the size of the winch you need to turn it). If you try 65 square feet and 65 mph, as you want, you'll get about 1200lb of force (550kg). I wouldn't even consider using this info for what you suggest are life and death matters, but it's probably right to within a factor of two.

It's not clear what you mean with your other factors. If the kite is tied down by unbreakable 25m wires, then it doesn't matter how strong the wind is. Changing the shape of the kite will have a big difference on the effective force it feels, though.

LeixlipRed

Hmmm I don't like that sentence about people's lives being in danger, could be dodgy legal ground here if anyone gives you bad advice. I'm going to lock this thread for the moment. OP, you can PM me if you'd like it re-opened or moved and you can provide me with some more detail, thanks.