follow Dictionary.com

Today's Word of the Day means...

conservation of mass

noun, Physics.
1.
the principle that in any closed system subjected to no external forces, the mass is constant irrespective of its changes in form; the principle that matter cannot be created or destroyed.
Also called law of conservation of mass, conservation of matter.
Origin
1880-1885
1880-85
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source
British Dictionary definitions for conservation-matter

conservation of mass

noun
1.
the principle that the total mass of any isolated system is constant and is independent of any chemical and physical changes taking place within the system
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Cite This Source
conservation-matter in Science
conservation of mass  
A principle of classical physics stating that the total mass of a closed system is unchanged by interaction of its parts. The principle does not hold under Special Relativity, since mass and energy can be converted into one another.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
Encyclopedia Article for conservation-matter

conservation of mass

principle that the mass of an object or collection of objects never changes, no matter how the constituent parts rearrange themselves. Mass has been viewed in physics in two compatible ways. On the one hand, it is seen as a measure of inertia, the opposition that free bodies offer to forces: trucks are harder to move and to stop than less massive cars. On the other hand, mass is seen as giving rise to gravitational force, which accounts for the weight of an object: trucks are heavier than cars. The two views of mass are generally considered equivalent. Thus, from the perspective of either inertial mass or gravitational mass, according to the principle of mass conservation, different measurements of the mass of an object taken under various circumstances should always be the same

Learn more about conservation of mass with a free trial on Britannica.com
Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
Cite This Source

Word of The Day

Difficulty index for conservation of mass

Few English speakers likely know this word

Word Value for conservation

17
21
Scrabble Words With Friends

Quotes with conservation-matter