The first speed limit was passed in England in 1865, setting a limit of 10 miles per hour on trains operating in the country. The first speed limit on automobiles also comes from England; in 1896, a limit of 14 miles per hour was set on what was called at the time "light locomotives". Local governments were given discretion to lower the limit to 12 miles per hour in their towns.
The federal government sets national speed limits by promising monetary incentives to states that cooperate with their legislature. The states can set their own limits but if they want aid from the federal government they must comply with their mandates.
Speed limits aren't in the Constitution. If you wanted to really reach you could say the 10th--any powers not reserved to the federal government devolve to the states--but that would be a big stretch.
2 hours 30 minutes, within speed limits
The higher enrichment needed the more enrichment and stripper stages needed. However the speed of enrichment depends more on how fast you can pump the uranium hexafloride through the individual stages without exceeding their limits. These limits will vary depending on enrichment technology used.
There are no time limits
Parts of the German Autobahn do not have posted speed limits.
speed limits and operation restrictions.
Yes Germany does have speed limits but on a lot of motorways they dont :)
They are not allowed to exceed speed limits
Speed limits are set by whatever level of government owns that particular roadway.
Posted speed limits tell you what the maximum speed is on that specific road. That is the speed that you are legally able to drive on the road.
Drivers need to be consciously aware of changing speed limits and watch for posted signs in city and suburban driving environments. You would expect: A speed limits of 15 mph B speed limits of 25 mph C speed limits of 35 mph You would not expect to see D speed limits above 45 mph City driving is referred to as "start and stop" driving because traffic is either moving or stopped. Changing speed limits can make traffic slow to a crawl, such as in school zones.
This depends on whether you are looking for aircraft speed limits or motor vehicle speed limits.
They are not allowed to exceed speed limits
Speed limits change for lots of reasons. Limits have changed to conserve fuel and for accident reduction.
not everywhere, but by default there is just a recommended speed (~80mph).
For safety.