chapter 1 describing motion (science)

reference point

the 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 positions

displacement

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

speed

the measure of the distance an object travels per unit of time

average speed

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

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

velocity

the speed and direction of a moving object

acceleration

a measure of the change in velocity during a period of time

average speed=total distance/ total time

average speed equation

m/s

SI unit for speed

acceleration= final speed - initial speed/ total time

acceleration equation

m/s/s

SI unit for acceleration

positive direction

the reference point is a _____ ______

negative direction

direction opposite the reference point is a _____ _____

to the north

an example of a reference direction

the position of the object has changed

statement that indicates motion has occurred?

distance, direction, reference point

complete description of position includes:

one direction

distance and displacement are equal only if the motion is in ____ ______

an object's position is its distance and direction from a reference point

How does the description of an objects position depend on a reference point?

the distance an object moves is the actual length of its path, its displacement is the difference between its initial and final position

What is the difference between distance and displacement?

straight line

constant speed is shown as ______ ______ on a distance time graph

faster speeds

steeper line on a distance time graph indicate ____ _____

constant speed

straight line on a distance time graph=

speed changes

curved line on a distance time graph=

slowing down

slope decreases and downward curve on a distance time graph=

stopping

horizontal line on a distance time graph =

speeding up

slope increases, upward curve on a distance time graph=

arrow

velocity is represented by an ______

speed

length of an arrow indicates _______

arrow

like velocity, acceleration can also be represented with an _____

increases or decreases

an acceleration arrow's direction depends on whether velocity _____ or ______

opposite

when velocity decreases, acceleration and velocity are in _____ directions

speed up, slow down, change direction

name three ways an object can accelerate

speed time graphs

used to show how speed changes over time

horizontal axis (x-axis)

on a speed time graph, time is shown on the ______ ____

vertical axis (y-axis)

on a speed time graph, speed is shown on the _____ _____

not moving at all

if acceleration of an object is 0 m/s/s , the object is at a constant speed or

acceleration

what is the term for a change in velocity?

accelerating

an object that has the same speed but changes direction is __________

the x-axis is time and the y-axis is distance

What are the axes on a distance-time graph?

the x-axis is time and the y-axis is speed

What are the axes on a speed-time graph?