Chapter 2: Describing Movement in One Dimension, 1-D Linear Kinematics
Glossary
2.0 Introduction
- kinematics
- the study of motion without considering its causes
2.1 Displacement
- position
- the location of an object at a particular time
- displacement
- the change in position of an object
- distance
- the magnitude of displacement between two positions
- distance traveled
- the total length of the path traveled between two positions
reference frame
an arbitrary location (or origin) and set of axes from which the position and motion of an object can be described.
total displacement
the sum of the individual displacements
2.2 Vectors, Scalars and Coordinate Systems
- scalar
- a quantity that is described by magnitude, but not direction
- vector
- a quantity that is described by both magnitude and direction
2.3 Time, Velocity, and Speed
- average speed
- distance traveled divided by time during which motion occurs
- average velocity
- displacement divided by time over which displacement occurs
- instantaneous velocity
- velocity at a specific instant, or the average velocity over an infinitesimal time interval
- instantaneous speed
- magnitude of the instantaneous velocity
- time
- change, or the interval over which change occurs
- elapsed time
- the difference between the ending time and beginning time
2.4 Acceleration
- acceleration
- the rate of change in velocity; the change in velocity over time
- average acceleration
- the change in velocity divided by the time over which it changes
- instantaneous acceleration
- acceleration at a specific point in time
- deceleration
- acceleration in the direction opposite to velocity; acceleration that results in a decrease in velocity
2.7 Falling Objects: Human Movement in the Vertical Direction
- acceleration due to gravity
- acceleration of an object as a result of gravity
free-fall
the state of movement that results from gravitational force only
