Physics Vocab

position

a measure of where the object is at a particular time with respect to some reference point

displacement

the change in position of an object

distance traveled

the total length of the path traveled between two positions

scalar

a quantity with magnitude or size, but no defined direction

vector

a quantity having both magnitude and direction

vector component

the projection of a vector quantity along an axis in a coordinate system

resultant

a vector that is the sum of two or more vectors

motion diagram

shows an object’s position at several equally spaced moments in time

dot diagram

a motion diagram in which each position of the moving object of interest is represented as a single point

uniform motion

Straight-line motion in which the position changes the same amount in each time interval

nonuniform motion

the position does not change the same amount in each time interval

position graph

conversion of a the dot diagram into a graph of position as a function of time

velocity

a measure of how much an object’s position changes in a specified amount of time

speed

a measure of how much distance an object travels in a specified amount of time

Instantaneous velocity

the average velocity over an infinitesimally small time interval

tangent line

a straight line through a pair of infinitely close points on a curve

time derivative

the rate at which the value of the function changes with time

acceleration

a vector that is the time derivative of velocity, and it is measured in m/s^2 .

constant accelerated motion

a constant acceleration

instantaneous acceleration

the average acceleration over an infinitesimally small time interval

equations of motion

v = vi + at and d=vit + 1/2at^2

integral

the area under a curve on a graph

free fall

An object falling without resistance under the influence of Earth’s gravity

acceleration due to gravity

body in free fall experiences a constant acceleration toward the center of Earth

projectile

an object that is moving through the air affected only by gravity

projectile motion

the combination of uniform motion parallel to Earth’s surface and free-fall motion, which has a constant acceleration perpendicular to Earth’s surface

trajectory

the path a projectile takes

trajectory graph

a two-dimensional dot diagram that shows the object’s total trajectory

uniform circular motion

when an object travels in a circular path at a constant speed

centripetal vector

a vector quantity that is always directed toward the center of a circle

centripetal acceleration

an object in uniform circular motion

oscillatory motion

any motion in which an object repeats the same movement over and over