4 ms·
Any wind that's strong enough to overcome static friction would do the trick, and I can't see why 10mph wouldn't be enough. The small models that you can build
by mumblemumble 5y ago
Any wind that's strong enough to overcome static friction would do the trick, and I can't see why 10mph wouldn't be enough.
The small models that you can build at home (sorry, can't find the plans anymore; this was 10 years ago now) do not require a push to get started.
- jrs235 5y agoUnderstandable that it doesn't take much wind for a vehicle well under a pound. But what about one that weighs well over 100 pounds?
- mumblemumble 5y agoThe 100 pound vehicle also has a much larger cross section to the wind. And its propeller is further off the ground, so it's getting cleaner wind than the little model version. I can get a boat that weighs more and has less sail area going on less wind than that. And that thing has to be dragged through the water on top of everything else.
- amluto 5y agoIn the water, there is no static friction and no velocity-independent friction. If you push a floating boat, it moves.
- deleted 5y ago[deleted]
- mumblemumble 5y agoFair point. Though, I would guess that Blackbird's internal mechanisms are well-enough engineered that it has very, very little static friction where it counts.
- wongarsu 5y agoIn the veratasium video [1] you can see it starting just from the wind (first attempt is around 5:20). It works just fine because as you scale up the vehicle you scale up the propeller, so there's plenty of surface for the wind to push against. 1: https://www.youtube.com/watch?v=jyQwgBAaBag https://www.youtube.com/watch?v=jyQwgBAaBag
- dharmab 5y agoMy motorcycle with me on it can weight 700-800 pounds and has a much smaller cross sectional area than blackbird. And yet it still gets pushed around sometimes by crosswinds .
- IntrepidWorm 5y agoIf I understand what you're saying though, you would be in motion on the bike as the crosswind pushes against you- it takes a lot less force to shift your heading while moving forwards than if you were being blown sideways while stationary. Unless I'm misinterpreting your statement- perhaps you have a hobby of riding in hurricanes, which would be rad. :)
- dharmab 5y agoI've definitely ridden through some storms that felt that way!
- raisedbyninjas 5y agoThe fan blades are an airfoil, which have a minimum speed to create the lifting effect.
- deleted 5y ago[deleted]
- mumblemumble 5y agoLift isn't really a part of how this gets started. Regular old pushing works on airfoils, too.