# Columbia Encyclopedia

39 results found

## acceleration

(Encyclopedia)acceleration, change in the velocity of a body with respect to time. Since velocity is a vector quantity, involving both magnitude and direction, acceleration is also a vector. In order to produce an ...

## D'Alembert's principle

(Encyclopedia)D'Alembert's principle dălˈəmbârzˌ [key], in mechanics, principle permitting the reduction of a problem in dynamics to one in statics. This is accomplished by introducing a fictitious force equal...

## inertia

(Encyclopedia)inertia ĭnûrˈshə [key], in physics, the resistance of a body to any alteration in its state of motion, i.e., the resistance of a body at rest to being set in motion or of a body in motion to any c...

## motion

(Encyclopedia)motion, the change of position of one body with respect to another. The rate of change is the speed of the body. If the direction of motion is also given, then the velocity of the body is determined; ...

## harmonic motion

(Encyclopedia)CE5 Harmonic motion is exhibited by a weight vibrating on the end of a spring. In A, the displacement of the object from its equilibrium position and the acceleration of the object are at a maximum...

## weightlessness

(Encyclopedia)weightlessness, the absence of any observable effects of gravitation. This condition is experienced by an observer when he and his immediate surroundings are allowed to move freely in the local gravit...

## torque

(Encyclopedia)torque, in physics, that which tends to change the rate of rotation of a body; also called the moment of force. The torque produced by rotating parts of an electric motor or internal-combustion engine...

## free fall

(Encyclopedia)free fall, in physics, the state of a body moving solely under the influence of gravitational forces (see gravitation). A body falling freely toward the surface of the earth undergoes an acceleration ...

## newton, unit of measure

(Encyclopedia)newton, abbr. N, unit of force in the mks system of units, which is based on the metric system; it is the force that produces an acceleration of 1 meter per second per second when exerted on a mass of...

## formula, in mathematics and physics

(Encyclopedia)formula, in mathematics and physics, equation expressing a definite fixed relationship between certain quantities. The quantities are usually expressed by letters, and their relationship is indicated ...