Friction is a force that arises when things rub against each other. Friction can slow things down and eventually make the surfaces wear down. Different objects have different amount of friction when they rub together. However, when surfaces do not rub against each other, there is no friction between them. The best way to reduce friction between two surfaces is to arrange them so that they do not touch!
Boat engineers and builders know that friction between a boat and water is one thing that slows the boat down. Over the years, they have been figuring out ways to design boats so that they do not touch water very much, but still float. In 1877, a British engineer named Sir John Thornycroft patented a method to design boats to ride on a cushion of air. Basically, his method was to use a large fan powered by a motor to force air down under the craft. Eventually, the air pressure was large enough to lift the vehicle off the surface.
Engineers took this idea and built upon it, designing “flying boats” and other airplanes that can lift off of a water surface. Finally, in the early 1950s, British, American and Swiss engineers began to think of new ways to use Sir Thornycroft’s air cushion idea. In 1955, a British man named Christopher Cockerell tested a new kind of craft and patented his idea for the first real hovercraft — a vehicle that can travel on a cushion of air over water, ice, dirt, pavement and other surfaces. Hovercrafts are so versatile that the Ford Motor Company even made a “hovercar” called the Glideair in 1959. Now, hovercrafts are used for rescue work on rapidly moving rivers and thin ice, cargo transport and ferrying work (such as across the English Channel), and by the military to transport troops and equipment from boats to the shore.
Dene D., PBS Kids
This resource is a part of the Engineering & Robotics lesson series.
This resource is a part of the Engineering & Robotics lesson series.
This resource is a part of the Engineering & Robotics lesson series.
