motion diagram

a series of images showing the positions of a moving object taken at regular (equal) time intervals

coordinate system

a system used to describe motion that gives the zero point location of the variable being studied and the direction in which the values of the variable increase

origin

the point at which both variables in a coordinate system have the value zero

position

the separation between an object and the origin; it can be either positive or negative

distance

a scalar quantity that describes how far an object is from the origin

magnitude

a measure of size

vectors

quantities, such as position, that have both magnitude and direction

scalars

quantities, such as temperature or distance, that are just numbers without any direction

resultant

a vector that results from the sum of two other vectors; it always points from the first vector's tail to the last vector's tip

time interval

the difference between two times

displacement

a change in position having both magnitude and direction; is equal to the final position minus the initial position

position time graph

a graph that can be used to determine an object's velocity and position, as well as where and when two objects meet, by plotting the time data on a horizontal axis and the position data on a vertical axis

instantaneous position

the position of an object at any particular instant in time

average velocity

The change in position, divided by the time during which the change occurred; is the slope of an object's position-time graph.

average speed

how fast an object is moving; is the absolute value of the slope of an object's position-time graph

instantaneous velocity

a measure of motion that tells the speed and direction of an object at a specific instant in time

velocity time graph

a graph that can be used to plot the velocity of an object versus time and to determine the sign of an object's acceleration

acceleration

the rate at which the velocity of an object changes

average acceleration

the change in velocity during some measurable time interval divided by that specific time interval; is measured in meters/sec sq

instantaneous acceleration

the change in an object's velocity at a specific instant of time

free fall

the motion of the body when air resistance is negligible and motion can be considered due to the force of gravity alone

acceleration due to gravity

te acceleration of an object in free-fall, resulting from the influence of gravity

projectile

an object's shot through the air, such as a football, that has a independent vertical and horizontal motions and, after receiving an initial thrust, travels through the air only under the force of gravity

trajectory

the path of a projectile through space