Answer: Lubrication
Moving parts of early machines were able to run because of the application of a lubricant such as oil, vaseline or grease.
The history of lubrication has advanced into a discipline known as tribology, which studies interactions between the moving parts of a machine.
By studying friction, wear, and lubrication, engineers are able to design bearings that prolong the useful life of rotating machinery.
They were all part of Nazi Germany persecution of the Jews.
<em>The Nuremberg Laws</em> were racial and antisemitic laws in Nazi Germany. They consisted of The Law of Protection of the German Blood and German Honor and The Reich Citizenship Law. The first one forbade marriages and sexual intercourse between Germans and Jews, the second one declared as German citizen people with German blood only. Due to the enforcement of these laws, non-Jews stopped socializing with Jews and started boycotting their businesses. Many Jews violating the laws were arrested by the Gestapo and killed or deported to concentration camps.
<em>Kristallnacht </em>( Cristal Night or Night of Broken Glass ) was a pogrom against Jews in Nazi Germany on the 9th and the 10th of November 1938. The name comes from all the broken glass left on the streets after the windows of Jewish-owned shops were smashed. The attacks were carried out by SA forces and civilians. Many Jewish stores, building and synagogues were destroyed. This event was followed by additional persecution of the Jews.
<em>The Final Solution</em> was a Nazi plan to exterminate (kill) the Jews during World War II. It was a code name for the murder of Jews all over the world as part of the Holocaust program. The Jewish victims were sent on death trains to various concentration camps or killed immediately. As the result of the final solution, 90% of Polish Jews were killed
Railroads helped the nations economy grow tremendously. It changed the entire Industrial revolution and made it more easier.
Rail roads helped the economy grow by:
-Transporting goods
-Use of transportation to and from places
-Rise the demand for materials
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Explanations:
The reason why rail roads helped the U.S economy was by transporting goods. Trains could carry tons of things in it and in a easily fashion, which made it easier to get things around. Trains helped businesses gets supplies around and made it less complicated. If there were no trains, the industry's during that time would be in a struggle because it would be complicated to transport things throughout the country.
Another reason why rail roads helped the U.S economy was by making it a reliable source of transportation. Before trains were invented, people used horses to travel from place to place, and that takes a very long time and is very exhausting. Trains solved the problem of transportation. Trains could carry many passengers and could take them to a certain destination as quickly as possible, while being safe.
Another reason why rail roads helped the U.S economy was by making the demands for certain materials rise. Materials like steel and wood were in very high demand because people needed a lot of quantities of steel and wood to make the rail road tracks. People sold wood and steel for a high price, which helped the economy a lot.