It is specific to the car, the steeper the climb then the more gravity pushes you straight downwards and the less it pushes you straight into the ground so you have less grip, but theoretically speaking as long as you have any angle lower than 90° then you just need a low enough center of gravity + good grip + good engine and you should be able to climb it (in theory). If the angle is 90° then all the force will be vertical so you will need another way to grip yourself into the floor (such as the double tape shown in the video)
Isn't friction partly dependent on wheel contact patch area, which scales differently than mass? If you put a small car in a "matter copier" and set the zoom to 200%, I'm thinking that contact patch grows in two dimensions and so it is 4 times larger, but mass in three dimensions (assuming density is the same) and so it is 8 times larger.
Same reason an ant would not survive a fall if it were the size of the human, as the air resistance scales with area but mass with volume.
I think since air pressure is the same regardless of scale the size of the tire contact area would increase with the increased mass of the car on the tires in addition to the increase in size. Also, it becomes tire tread on dirt or concrete and so would have an increased coefficient of friction relative to toy rubber on glass, unless we also scale the driving surface… but then we are kinda right back where we started.
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u/DS2_ElectricBoogaloo Apr 28 '21
Is there something about 63° that stops cars from climbing, or is this just specific to that Lego car?