# How to calculate what wind speed is required to lift 1kg? [closed]

as the title says, i want to calculate how much km/h is required to lift 1kg of weight. Please explain this to me as simple as you can since i'm really noob in this. Thanks.

• Can you share more on your application? what are you doing? why? – Mark Omo Feb 2 '17 at 23:51
• If you use a balloon, it doesn't require any wind speed at all. Are you talking about some kind of kite? What is the significance of the motor tag? – Dave Tweed Feb 3 '17 at 14:13
• Welcome to Robotics n_n, but I'm afraid that it is not clear what you are asking. We prefer practical, answerable questions based on actual problems that you face, so it's a good idea to include details of what you want to achieve, what you tried, what you saw & what you expected to see. Please take a look at How to Ask & tour for more information on how stack exchange works and work through the Robotics question checklist to edit your question to make it clearer. – Mark Booth Feb 3 '17 at 15:55

That is a very difficult question and as far as I know it is nearly impossible to answer in that way. You need to define the "sail" you use further. Read this and specify your problem further.

Perhaps this is enugh for you:

Energy of moving air

$E = \frac{1}{2} \cdot \rho \cdot A \cdot v_{wind}^3 \cdot t$

where:

• E - Energy
• $\rho$ - Density of air
• A - Area of the sail
• v - velocity of the wind
• t - time

Energy of lifted weight

$E = m \cdot g \cdot h(t) = m \cdot g \cdot v_{lifitng} \cdot t$

where:

• m - mass of the object
• g - 9.81 m/s^2
• h(t) - height at time t

Assuming that you have a system which can convert the wind energy in a perfect way to potential energy, than you can at least calculate some boundary values. If you want your question answered, specify the geometry of the sail, wind angle etc. further.