Describing Motion

reference point

starting point you choose to describe the location, or position, of an object

position

an object's distance and direction from a reference point

motion

the process of changing position

displacement

the difference between the initial (first) position and the final position of an object (vector quantity)

distance

how much ground an object has covered during its motion (scalar quantity)

scalar

quantities that are described by a magnitude (or numerical value) alone

vector

quantities that are described by both a magnitude and a direction

speed

a measure of the distance an object travels per unit of time (scalar quantity)

constant speed

the rate of change of position in which the same distance is traveled each second

instantaneous speed

speed at a specific instant in time

average speed

the total distance traveled divided by the total time taken to travel that distance

average speed formula

Total distance ÷ Total Time

velocity

the speed and the direction of a moving object (vector quantity)

units for speed & velocity

meters per second (m/s)

acceleration

a measure of the change in velocity during a period of time (vector quantity)

average acceleration formula

Final V - Initial V/Final Time -Initial Time

units for acceleration

meters per second per second (m/s/s or m/s^2)

p-t graph - object at rest

p-t graph - constant, positive velocity

p-t graph - constant, negative velocity

p-t graph - accelerating in the positive direction

p-t graph - accelerating in the negative direction

p-t graph - decelerating in the positive direction

p-t graph - decelerating in the negative direction

p-t graph - constant positive velocity, then higher constant positive velocity

p-t graph - higher constant positive velocity, then lower constant positive velocity

v-t graph - constant positive velocity; no acceleration

v-t graph - object at rest

v-t graph - constant negative velocity, no acceleration

v-t graph - positive acceleration