An object has kinetic energy when itâs in motion. The amount of kinetic energy an object has depends on its mass and speed. Potential energy, on the other hand, is a stored energy when an object is at rest. It describes how much work the object could do if set into motion. Itâs an energy we can generally control. When an object is set into motion, its potential energy transforms into kinetic energy.
The Knights of Labor, the first national industrial union in the United States, was founded in Philadelphia on December 9, 1869, by Uriah Stephens (1821-82) and eight other Philadelphia garment cutters.
Labor Day was promoted by the Central Labor Union and the Knights of Labor, which organized the first parade in New York City. In 1887, Oregon was the first state of the United States to make it an official public holiday. By the time it became an official federal holiday in 1894, thirty U.S. states officially celebrated Labor Day. Canada's Labour Day is also celebrated on the first Monday of September. More than 80 countries celebrate International Workers' Day on May 1 â the ancient European holiday of May Day â and several countries have chosen their own dates for Labour Day.