Slug
The slug is a unit of mass used primarily in the U.S. customary system and British engineering contexts.
1 slug = 32.174 pounds (lb) (mass)
Equivalent to approximately 14.5939 kilograms (kg)
Defined so that when a force of one pound-force (lbf) acts on a mass of one slug, it accelerates at 1 ft/s² (using F=ma in imperial units).
Key Facts:
Used mainly in physics and engineering for calculations involving Newton’s second law in imperial units
Allows consistent use of pound-force and pound-mass without extra conversion factors
Useful in dynamics, ballistics, and engineering mechanics
The slug bridges the gap between force and mass in the imperial system, making calculations easier when using pound-force units.
Exagram [Eg]
The exagram is a unit of mass in the metric system, representing a very large quantity.
1 exagram = 10¹⁸ grams
1 exagram = 1 billion billion grams (1,000,000,000,000,000,000 g)
1 exagram = 1,000,000,000,000 kilograms (10¹⁵ kg)
Symbol: Eg
Key Facts:
Used for measuring extremely large masses, often in astrophysics or planetary science
Rarely used in everyday measurements due to its enormous size
Part of the SI (International System of Units) prefixes based on powers of ten
The exagram helps describe massive objects or quantities on a cosmic or geological scale.