Motion Graphs
Displacement – Time Graphs
 Also known as position – time graphs
 Plotting displacement against time can tell you a lot about the motion of an object.
Time is always plotted on the X-axis. The
further to the right on the axis, the
longer the time from the start.
Displacement is plotted on the Y-axis.
The higher up the graph, the further
from the start.
If an object is not moving, a horizontal line
is shown on a displacement-time graph
Time is increasing to the
right, but its displacement
does not change, The
object is not moving. We say
it is at rest.
If an object is moving at a constant speed, it means
it has the same increase in displacement in a given
time.
Time is increasing to the right,
and displacement is increasing
constantly with time. The object
moves at a constant speed.
Constant speed is shown
by straight lines on a
graph.
Let’s look at three moving objects:
A steeper line indicates an
object that is moving at a
higher velocity
All the lines are straight so
all the velocities are
constant.
Let’s look at an object that is accelerating
The line on this graph is curving upwards.
Look at the slope of the line at point A
and B.
What do you notice about the steepness?
This shows an increase in speed.
A curved
line means an object is
accelerating.
Summary: Displacement-time graph
Answer the questions for the position vs. time graph
on the first page of the graphical analysis practice.
Velocity-time Graphs
Velocity-time graphs look much like
displacement-time graphs. BE
SURE
TO READ THE LABELS. Time is
plotted on the x-axis. Velocity is plotted
on the Y-axis.
Velocity Time Graph
A straight horizontal line on a velocity-time graph
means that the velocity is constant.
A straight line on a velocity-time graph
does not mean the object is not moving.
The slope of a velocity time graph for an object is
the value of the acceleration of the object.
No slope – No acceleration
Velocity-time Graph
This graph shows increasing velocity. As time
increases the velocity value is also
increasing.
The object is accelerating
Positive slope – Positive acceleration
Positive velocity and positive
acceleration – object is speeding up
Velocity-time Graph
This graph shows an object with
decreasing velocity.
As time increases the value of velocity
decreases.
Negative slope – negative
acceleration
Positive velocity and negative
acceleration – object is slowing
down
Summary
Answer the questions for velocity time graphs on the
back of the first page.
Velocity-time graph can also be used to
find the displacement of an object.
Velocity-time Graph
Acceleration-time Graph
Acceleration in our class will always be a
constant value so the lines will always be
horizontal on an acceleration time graph.
Lines above the 0 line indicate a positive
acceleration. (positive slope on a
velocity-time graph)
Lines on the 0 line indicate no
acceleration. (no slope – horizontal line
on a velocity-time graph)
Lines below the 0 line indicate a negative
acceleration. (negative slope on a
velocity time graph)
Answer the questions for the last Velocity graph on
the front and back of the second page.
Describing Motion with
Diagrams
Describing Motion with Diagrams
 Ticker Tape Diagrams
Ticker Tape Diagrams
The distance between dots represents the object’s change in position during that time
interval
Ticker Tape Diagram
A changing distance between dots indicates a changing velocity – acceleration
Answer the ticker tape questions