inertia

inertia

Physics

a. the tendency of a body to preserve its state of rest or uniform motion unless acted upon by an external force

b. an analogous property of other physical quantities that resist change

Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005

Inertia

That property of matter which manifests itself as a resistance to any change in the motion of a body. Thus when no external force is acting, a body at rest remains at rest and a body in motion continues moving in a straight line with a uniform speed (Newton's first law of motion). The mass of a body is a measure of its inertia. See Mass

McGraw-Hill Concise Encyclopedia of Physics. © 2002 by The McGraw-Hill Companies, Inc.

inertia

(i-ner -shă) The property of a body by which it resists change in its velocity. It is inertia that causes a body to continue in a state of rest or of uniform motion in a straight line (see Newton's laws of motion). The force required to give a specific acceleration to a body depends directly on its inertia. It is through the property of inertia that the concept of the mass of a body (its inertial mass) arises.

Collins Dictionary of Astronomy © Market House Books Ltd, 2006

inertia

[i′nər·shə]

(mechanics)

That property of matter which manifests itself as a resistance to any change in the momentum of a body.

(medicine)

Sluggishness, especially of muscular activity.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Inertia

 

in mechanics, a property of material bodies that is reflected in the first and second laws of mechanics. When there are no external influences (forces) acting on a body or when they are mutually balanced, inertia is manifested in the fact that the body maintains unchanged its state of motion or rest with respect to the so-called inertial frame of reference. If, however, an unbalanced system of forces acts on the body, then the property of inertia is manifested in the fact that a change in the body’s state of rest or motion, that is, a change in the velocities of its points, takes place gradually and not instantaneously. Here, the greater the inertia of the body the more slowly the motion changes. The mass of a body is the measure of its inertia.

The term “inertia” is still used with respect to various instruments; the inertia of an instrument is its property of displaying readings with a certain delay.

S. M. TARG

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.