Convert Quarter (US) to Slug

The quarter originated in medieval England as a unit of mass for measuring grain and other agricultural products. It was defined as 1/4 of a hundredweight, or 25 pounds. The term "quarter" comes from the Latin word "quartarius", meaning "fourth part". The quarter was used in trade and agriculture for centuries and was adopted in the United States as part of the U.S. customary system.

The slug was introduced in the late 19th century as part of the foot-pound-second (FPS) system, which was developed to be more consistent with the principles of mechanics, particularly Newton's second law of motion. The term "slug" was chosen because it represented a unit of mass that would help express the relationship between force, mass, and acceleration in a way that was easier to apply in engineering and scientific calculations. The slug is used primarily in the U.S. and some engineering contexts, but it is less common in everyday measurements, where the pound is typically used for mass and weight.