how does a sailboat or other wind-powered device get back where to it started?
467716
When you sail, you cut across the wind at an angle. The more you turn into the wind or sheet in the sail, the faster you go. To get back where you started from you 'tack' into the wind at a sharp angle, then turn the other way in a zig-zag pattern. The sail tries to push the boat back but the hull and keel cut into the water so you actually move into the wind
71390
Wind power, although the ships were of different design.\nPinta and Nina were caravels known as "Tudor Caravel" (2nd link) \n Santa Maria was a carrack (3rd link)
916449
probably gravity. it's the most likely. without gravity there would be no wind, running water or sea waves. think about it for a second it'll make sense
520750
When swimming in the ocean, have you ever wondered why you tend to be carried down the beach, away from your towel in an undertow? \n\nThe answer is simple. This process is called longshore drift and is generated by wave and current action. \n\nWater and sediment are transported in a zig-zag pattern as waves and currents approach the shoreline at an angle. This zig-zag pattern is the mechanism for sediment transport as the swash is immediately followed by the backwash to the ocean. This energy created from the breaking waves allows for weak currents to carry large amounts of coarse-grained sediment down the shoreline. These weak currents, known as longshore currents, carry water and sediment parallel to the shoreline toward the downdrift end of the beach
469524
It has to do with high and low pressure systems. Wind moves from high-pressure areas to low-pressure areas.
276362
in the unconstrained case (no floor), water from the lowest hole will reach the furtherest given enough time (vertical space to drop). With a vertical constraint (a floor), the optimal coverage will be from a hole one third the way up from the floor, not the top hole near the surface of the water, and not a hole at floor level.\n\nAlthough I really don't see how this applies to wind sailing:-)
1063787
"Wind is the roughly horizontal movement of air (as opposed to an air current) caused by uneven heating of the Earth's surface. It occurs at all scales, from local breezes generated by heating of land surfaces and lasting tens of minutes to global winds resulting from solar heating of the Earth. The two major influences on the atmospheric circulation are the differential heating between the equator and the poles, and the rotation of the planet (Coriolis effect)."
1140242
The wind exerts more pressure on the open side of the cups than it does on the rounded side, so that no matter which direction the wind is coming from, the cups will spin.  Wind velocity is calculated by the speed of the spin -- rotations are counted and divided by the time of measurement.  It was invented in 1846 but didn't really become accurate until electrical spin counters and timers were added.
516448
Sails can go against the wind but not ireactly into it. There is about 90degrees, 45degrees either side of the direction that boats with sails struggle into.\n\nThe sail is shaped much like an aeroplane wing and it is this shape that forces the air to move fater over one side of the sail than the other, decreasing air pressure on one side of the sail and pulling the boat along. This will pull the boat in a slighlty side on motion to the desired travel but a central board (dagger board) creates sideways resistance and forces the forward  motion to be dominant.
653017
I would start with the sun. It is the source of all the energy we get. It made the plant grow that the dinosaurs ate that we get fossil fuel from. It causes the weather that we can get wind energy or tidal energy, or we can get solar power directly. Yup.. start with the sun and trace every kind of energy you can think of back to it.
717976
boats.\n\n\nAnd water.  Lots of water.
383729
It has a dynamo inside it, when you wind it up, that is the driving force for the energy.
151159
The vessel being overtaken is always stand-on and has the right of way.  Typically a sailboat has right of way over a powerboat but in a overtaking situation, if a sailboat is ovetaking a powerboat the powerboat is stand-on and has right of way.
170057
The wave generation systems ive seen recently dont use a turbine. These contraptions are shaped like a snake and bob up and down with the waves. The pitching motion move pistons that turn generators.
479534
A turbind spins in a flat trajectory parallel to the land and generates electricity. A windmill spins vertically and does not develop a rapid speed, but is used to primarily grind grain.
973527
That's an urban legend.  Windmills are generally set up to rotate in a way that makes the most out of the prevailing local wind.  If you look at windmills you will find that they do not all rotate the same way.
459186
This sounds like a nautical question indeed!\nHmmmmm...