[00:02] Here I have a little cart with a big wheel that rolls on two smaller spools. And what I'm going to show is that when you have two media moving relative to one another, well then if this car is in contact with both media, it can actually
[00:18] velocity. >> [music] >> So as I push the board to the right, you can see that the car goes down the board faster than the board is moving.
[00:33] If you look carefully, you'll see that the big wheel isn't turning the way that the board is pushing it. It's actually rotating in the opposite direction. That's just like the propeller on Blackbird, which pushes [music]
[00:47] back against the air and that's how it's able to go faster >> than the wind downwind. Now you can build one of these cars for yourself at build one of these cars for yourself at home or you can build a model downwind
[01:00] home or you can build a model downwind cart.