question: How are flimsy devices like wheel chocks and jack stands able to hold a 4000lbs car?
comment: Well, chocks just keep wheels from rolling, they don't need to be able to handle any weight. Jackstands are made of steel, and steel is extremely strong for it's weight.
passages: depending on the car size and trailer model (capacity is limited by an 80,000 lb weight cap that a road vehicle is subject to under U.S. law.). Significantly higher-capacity vehicles have been observed around the world, such as a side-by-side loading Chinese model.
   Some sidelifters have a telescopic chassis, sometimes called trombone chassis, allowing the unit to expand and contract in order to accommodate 20 ft, 40 ft or even 45 ft containers. These Trombone units are specially suited for small secondary roads where cornering is quite difficult with 40 ft trailers.
  
  Section::::Safety.
   Some modern automobiles (such as Audi's Allroad Quattro) have adjustable suspension systems, which can vary the ride height by locating the suspension mounting points, depending on road conditions and/or the settings selected by the driver.
  
  Other, simpler suspension systems, such as coilover springs, offer a way of manually adjusting ride height (and often, spring stiffness) by compressing the spring in situ, using a threaded shaft and adjustable knob or nut.
   The ratio of container length to chassis length is a factor in achieving rated load capacity. This ratio determines the load angle, and all hooklift hoist systems indicate a recommended range of body lengths, typically difference in length between the container and the chassis. Container bodies shorter than the recommended length produce substantially steeper load angles, and consequently lower load rating, than those of the longest bodies intended for use with a particular hoist. 
   Section::::Typical equipment.
  
  The most common form of Statnamic rigs typically have testing capacities of 3 to 4MN. These devices are self-contained and may be transported using a single articulated lorry. Whilst on site they require the use of a mobile crane with a typical capacity of 70 tonne, with mobilisation in less than 2 hours. In addition to these typical capacities, devices have been produced which can apply maximum loads ranging from 0.3 to 60MN. To achieve greater loads the major components of the device including the piston, silencer-weight hanger and reaction mass must be scaled up in size.
   It consists of four inclined pillars which support a revolving arm. On one end of the arm are some counterweights and on the other is a rotating hub which holds 10 cars. The minimum height requirement is or taller. Portable Fabbri units break down on to two trailers. Set up requires around 5–6 hours for the ride's assembly. The original ride was manufactured in 1992 by Nauta Bussink (now Ronald Bussink). Bussink built only three Evolutions. Evolution formerly travelled the European circuit before it was sold to Six Flags Great Adventure in 1999 and relocated to Six Flags St. Louis during the 2002 off-season. The second one, dubbed Imperator, was sold to a showman in China. The third model is said to be in storage in the Netherlands. It was last seen travelling with the Dutch carnival company Magic Fair Attractions.
   BULLET::::1. A pair of CV or universal joints is required for each wheel, adding complexity, cost, and weight.
   For a given "rated load" wire rope is lighter in weight per unit length but overall length is limited by the drum diameter that the cable must be wound onto. The lift chain of a chain hoist is far larger than the liftwheel over which chain may function. Therefore, a high-performance chain hoist may be of significantly smaller physical size than a wire rope hoist rated at the same working load.
   The original Schaper Toys Stomper / Stompers (toy) vehicles of 1980 and subsequent Tamiya replicas of 1982 were heavily influenced by the worldwide craze for 4WD vehicles that started in 1979 with the inaugural running of the Paris Dakar Rally in 1979, which is evidenced by the particular make of those models.
  
  In 1982, a Japanese company, Tamiya, produced their own replica versions of the 1/32 scale Schaper Toys Stomper / Stompers (toy) that utilized worm gears and spur gears.
   As constant improvements were being made, the National University of Singapore (NUS) decided to make even further advancements by inventing a mechanical arm that can lift up to 80 times its original weight. Not only did this arm expand its lift strength, but the arm could also extend to five times its original length. These advancements were first introduced in 2012 and car companies can greatly benefit from this new scientific knowledge.
  
  Section::::History.:Surgical Arms.
   Pictured is an early example of an approximately 1:64 slot car built by Aurora around 1972, as part of its AFX line. This first-generation AMC Matador coupe NASCAR race car replica is designed to fit on an enlarged chassis for nominal HO track.
   The Terrex AV81 was initially developed in 2000 by Timoney for Singapore Technologies Kinetics. The initial design utilised conventional coil springs shock absorbers but later variants have seen the introduction of hydro-pneumatic struts with real-time damping control. An electric-hybrid drive system was also developed.
  
  The Terrex AV82 was developed in 2005 equipped with a more advanced driveline and hydro-pneumatic suspension system. Development of this driveline involving new traction control systems and rear wheel steering continues.
  
  Section::::Military.:CM-25 and CM-31.
   An F1 car can be no more than 200 cm wide and 95 cm tall. Though there is no maximum length, other rules set indirect limits on these dimensions, and nearly every aspect of the car carries size regulations; consequently the various cars tend to be very close to the same size.
  
  The car must only have four wheels mounted externally of the body work with only the front two steered and only the back two driven. There are minimum distances allowed between the wheels and the rear and front body work.
   Section::::History.
  
  In 1980, the first, real mini 4WD series of vehicles, called Stomper 4x4 / Stompers (toy), were 1/32 scale and invented by Adolph Eddy Goldfarb and produced by Schaper Toys of Minnesota, USA. Later, from 1983 to 1986, a smaller version of Stomper was distributed in McDonald's Happy Meals. A multitude of replicas produced by other companies led to lengthy lawsuits, and eventually the company sold the product to Tyco, after which, sales declined.
   VESC would cope with a roof before reaching 2.4 m height without pushing more than 75 mm.
  
  The headrests were folded into the seats and folded upwards. 
   Section::::Principle of operation.
   BULLET::::2. By winches and wires, hydraulic cylinders and lift and lock climbing mechanisms. In each of these cases the weight of the linkspan’s outer end keeps them always under load even when not in use. The load is further increased when the traffic passes over them.
   Ride attendants put the fiberglass shells down to lock in their harnesses. However, on Ultra Twister models, the stations had conveyor belts to allow guests access to a car. This ride opened with seven trains. It currently runs with two, allowing the others to be spare.
  
  Section::::Ride experience.
   The only product of the Modec company was the Modec EV commercial vehicle. It was produced in three versions; a chassis cab, box van and a dropside. All three shared a common wheelbase of and a steel ladder frame chassis. The Modec has a kerb weight of 3.3 tonnes and a max gross capacity of 6.05 tonnes.
   Exoskeleton car
  
  An exoskeleton car has a visible external frame, being made of steel, aluminum or carbon fiber tubes. 
  
  Body styles are open wheel sports cars, with their wheels outside of the main body and each wheel covered by its own lightweight mudguard, usually carried as unsprung weight supported on the hub carrier. The chassis has four large longitudinal tubes, two on each side of the car body, inboard of the wheels. These main chassis tubes are spaced apart by smaller diagonal or vertical tubes.
   Flexible bollards are bollards designed to bend when struck by vehicles. They are typically made from synthetic plastic or rubber that is stiff on its own, but pliable under the weight of a car or truck. When struck, flexible bollards give way to some extent, reducing damage to vehicles and surrounding surfaces, and return to their original, upright position. Some flexible bollards do not provide physical protection from vehicles; rather they offer clear visual guidance for drivers. Other flexible bollards have been designed to provide physical protection as well as reduced damage by incorporating strong elastic materials. These can be all plastic or plastic/steel hybrids but combine varying degrees of stopping power and flexibility.
   Section::::Design.
  
  The movement of vehicles between floors can take place by means of:
  
  BULLET::::- interior ramps – the most common type
  
  BULLET::::- exterior ramps – which may take the form of a circular ramp (colloquially known as a 'whirley-gig' in America)
  
  BULLET::::- vehicle lifts – the least common
  
  BULLET::::- automated robot systems – combination of ramp and elevator
  
  Where the car park is built on sloping land, it may be split-level or have sloped parking.
   Section::::Investigations.:Denby 44 tonne legal challenge.
   Some cars have used underslung frames to achieve a lower ride height and the consequent improvement in center of gravity. The brass-era cars of the American Motor Car Company are one example.
  
  Self-leveling suspension systems are designed to maintain a constant ride height regardless of load. Vehicles not equipped with self-leveling will pitch down at one end when laden; this adversely affects ride, handling, and aerodynamic properties.
   After removing and inverting the detachable slot-car pin, the cars could also be run on the floor, with the front wheels steerable into one of three set positions (left, center, right), held by small detents on the reverse side of the pin.
  
  Although some playsets were marketed to feature competitive play between two operators ("Racerific"), in truth there was little allowance for competition since there was no operator control over speed.
  
  Motorific vehicles and accessories remain popular as collectibles, particularly with baby boomer toy aficionados.
  
  Section::::Marketing.
  
presuppositions: Jack stands shouldn't be able to carry a car. Wheel chocks need to hold up a 4000 pound car.
corrections: Jack stands are made of steel which is very strong. Wheel chocks don't need to handle any weight.
raw_presuppositions: Jack stands shouldn't be able to carry a car. Wheel chocks need to hold up a 4000 pound car.
raw_corrections: Jack stands are made of steel which is very strong. Wheel chocks don't need to handle any weight.