Volume vs. Capacity
Date: 05/01/2002 at 18:55:51 From: Lydia Saxton Subject: Volume vs. Capacity Can you explain the difference between the terms "volume" and "capacity"? Most sources I've researched seem to lean toward reserving the use of the term "volume" for solids (measured in cubic units) and the term "capacity" for liquids. Is this accurate? Also, can you define the distinction between "weight" and "mass"? Many texts use these terms interchangeably. I know that weight is a function of gravity and mass has to do with atomic structure, which is not affected by gravity. Thanks for your elucidations! A Math Coach for the Los Angeles Unified School District.
Date: 05/01/2002 at 23:01:11 From: Doctor Peterson Subject: Re: Volume vs. Capacity Hi, Lydia. I would say that volume refers to the space taken up by an object itself, while capacity refers to the amount of a liquid or other pourable substance a container can (or does) hold. That more or less parallels what you have seen. I have never, however, seen both terms used of the same object without clarification; you wouldn't talk of the volume of a pitcher, meaning the amount of plastic it is made of, without carefully saying so, since it is so common to use the two terms interchangeably. My dictionary gives "capacity" as a synonymous definition of "volume," though the current edition has backed away from that somewhat; here's the online version: http://m-w.com/ volume 3 : the amount of space occupied by a three-dimensional object as measured in cubic units (as quarts or liters) : cubic capacity capacity 2 a : the potential or suitability for holding, storing, or accommodating b : the maximum amount or number that can be contained or accommodated <a jug with a one-gallon capacity> <the auditorium was filled to capacity> In the dictionary's tables of units, as usual, "capacity" is used as the heading for "liquid measure" (gallons, etc.) and "dry measure" (bushels, etc.), and "volume" for cubic units. The former are used, as I suggested, to measure "pourable" substances, the latter for anything (since you can convert gallons to cubic feet to see how much space it takes up). But while I would use the term "capacity" to describe the unit, I would not speak of the number of gallons of milk as the "capacity of the milk," but as its volume - since, as I said, "volume" refers to the amount of a substance itself, and the milk is not a container. So really, capacity applies not to the liquids, but to containers. It's the "units of capacity" that are used for liquids. As for mass and weight, this should cover it: Mass vs. Weight http://mathforum.org/library/drmath/view/56250.html Mass vs. Weight http://mathforum.org/library/drmath/view/56320.html Mass versus Weight http://mathforum.org/library/drmath/view/56334.html - Doctor Peterson, The Math Forum http://mathforum.org/dr.math/
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