Why do gravel roads always eventually form a very uniform and bumpy washboard pattern?
482982
These washboards tend to exist more at points where vehicles slow down and speed up. The action of the wheels in accelerating or slowing down tend to make the gravel pile up in little ridges.\n\nThis feature can also be seen on some asphalt roads that have only a thin layer of asphalt.
652833
A - A meander is a bendy bit of a river.\n\nC - A strange example though. A & B are physical/mechanical weathering and D is through the action of flora/forna. I'm not sure C actually happens often but it is the only chemical action.\n\nB - Limestone will dissolve in a weak acid. Another formation it produces are limestone pavements.\n\nHope this helps
1018342
It is kind of a hodge-podge of weight of the particles and the order in which they are deposited.  When a rock face of sediment is cut in half, you will see large particles sporactically throughout the rock section, but most will be at the bottom of their respective layer.  Sedimentation is a very tricky topic because it also depends on the geometry of the particles.
858812
Not sure about a website but the physics would be similar to what causes corrugations in a dirt road.  The vibration frequency would be related to the speed of the wheels.
725507
It is a slow movement of soil or weathered bedrock in sloping conditions where the driving force for the movement is the soil' own weight.  Slope creep is difficult to observe on its own but its effects on other things is easily seen.  For example, if you've ever seen a utility pole or fence that has been constructed on a steep slope and then over time you'll see the poles or fence has begun to lean or tilt out towards the bottom of the slope, that tilted is because the soil has "creeped" down hill and taken the pole or fence with it.  This type of mass movement is more prevelant in clayey (fine-grained) soils.\n\nSand dunes growing ans shrinking, however, is more realted to winds blowing sand grains around, not really slope creep.
1171684
Erosion breaks up igneous and metamorphic rocks, and the particles build up to create sedimentary rocks.  \n\nHope this is helpful.
1127654
theres some nice crushed gravel trails around here, that used to be railroad tracks.  great because its softer than asphalt, and not many hills.
848599
No. The velocity of the wheel is changing as the car moves (because velocity indicates direction). So as the car moves forward, the velocity of the surface of the wheel is continuously changing.
1133306
Each province has its own regulations, but a lot of them are based on american standards for Ashpahlts and rigid pavements.  The crust or surface course is actually only one of several layers of asphalt and aggregate the make up the roadway.  The thichness of each of the layers is depedent upon the underlying soil, the conditions that the highway will face and the use of the high way including the amount of traffic but especially truck traffic as they do the most damage to the road surface.  This data is then converted to an ESAL equivalent 80 kN single axle load and the thicknesses of various layers can be looked up in a series of tables.
1147005
It's just patterns created by the irrigation equipment.\n\nCrop circles, people? Sure hope yer kidding...
662877
Mudslides..... ewwwwwwwwwww
490009
Because the normal force of the road upon the car is not directed straight upwards, as it is on a flat road. The normal force vector is tilted inward toward the center of the radius of curvature (assuming that the road engineers built the darned thing correctly) by an amount equal to the angle of the bank of the road. Decomposing the normal force vector into a horizontal (towards the center of the circle) and a vertical (up towards the sky) shows an increased force upon the car towards the center of the radius of curvature over the case where the road is flat. In the end, it means that the coefficient of static friction that keeps the wheels from sliding radially away from the center of curvature doesn't need to be as high when the road is banked.\n\nAlso note: There is NO SUCH THING AS CENTRIFUGAL FORCE! The car is an accelerating reference frame. Anyone who uses the term "centrifugal force" either has not taken 1st year physics or did not understand it when they did.
20791
Most potholes are caused when water seeps into the pavement surface and eventually freezes, creating pressure as it expands. This weakens the pavement surface and as vehicles pass over, it breaks the area into smaller pieces. \n\nEventually the pieces vacate the cavity and a pothole is created. If a pothole isn't fixed in a timely manner, and additional water invades it, erosion will be accelerated and the pothole will become more pronounced.
284537
They are ridges in the concrete. It's supposed to make a roaring sound to alert drivers that they are running off the road. My Dad calls then waa waa lines because of the sound they make.
1177357
Friction, it's the same reason your tires make that sound if you try to come to a stop too quickly.
623326
Because they always spend the money on roads that don't really need repaving and cause traffic jams and accidents.  I was in an accident due to a crappy job of road workers giving ample warning that traffic on an interstate was about to come to a halt at the bottom of the hill.
467968
Sedimentary rock forms relatively flat. Youngest always on top of the oldest. Just like a stack of newspapers if you were to accumulate them everyday.\n\nFolding from compressional stress is one. Rock is literally pushed together creating anticlines & synclines, upward folding & downward folding arches respectively.\n\nFaults can also do this. This can be accomplished through compressional (pushed together) or tensional (pulled apart) stresses.\n\nI am not too sure about this one but isostatic adjustment could possibly tilt rocks.\n\nHope this helps.\n\n:)