Speed, Velocity and Graphs
Get colored pencils are multiple
colored highlighters if you have them
Review: Speed vs. Velocity
• Speed describes how fast something travels in
a given amount of time
• Velocity is a vector quantity that describes
how fast and in what direction and object is
moving
• Vector quantities can be shown on diagrams
with arrows.
• The length of the arrow represents the
relative speed and the direction it is pointing
represents the direction of movement
Reading Graphs
Quick graphing review:
• X axis is the horizontal axis, this is the
independent variable
• Y axis is the vertical axis, this is the dependent
variable
How do you Graph Motion?
General Understandings - 1
For distance vs. time graphs –
If we look at the graph
shown, you can see that the
time in hours is along the
horizontal, and the distance
in miles is on the vertical axis.
This graph represents a
journey that Jan took, in
travelling to Dallas and back,
from Austin.
Distance Time Graphs
• Think of these as
“journey” graphs!!
Watch this video
• Distance – time video:
https://www.youtube.com/watch?v=9LQdLDD
EJ1g&feature=youtu.be
Packet:
Packet Instructions:
• Read and highlight important information in
the packet. I will demonstrate what this
means.
• Work any “problems” you come across.
• Stop when you get to page 7.
• We will go over this section of the packet
together before continuing
No Motion
• Time is increasing,
but distance does
NOT change. It is
NOT MOVING…NO
MOTION…AT REST.
CONSTANT SPEED
• Time and
distance are
INCREASING at
a constant
rate. This
graph shows
CONSTANT
SPEED.
CONSTANT SPEED
• This graph is the
same as above, but
shows a change in
direction (meaning
the object is headed
back to the starting
point). This graph
also shows
CONSTANT SPEED.
FASTER SPEED
• A steeper line
shows greater
distance
traveled in a
given time.
The STEEPER
THE LINE, the
HIGHER THE
SPEED.
ACCELERATION
• In a given time,
the distance the
object moves is
getting larger, it
is
ACCELERATING.
The curve
upward shows
an INCREASE in
SPEED.
DECELERATION
• This graph is
the same as
above, but the
curve
downward
shows a
DECREASE IN
SPEED or
DECELERATION
Putting it all together
Main Points
•
•
•
•
•
A straight diagonal line shows constant speed.
A curved line shows average speed.
A horizontal line shows no motion.
Time is on the x-axis, distance is on the y-axis.
The steeper the line, the faster the motion.
Demo!
• Gizmo Lab Demo:
Speed/Velocity Time Graphs
General Understandings - 2
Speed (or velocity) vs. time
graphs
• The steeper the
gradient of the line (the
slope), the greater
the acceleration (a
bigger change in speed
in the same time).
Speed Graphing Videos
• Speed – Time Graphs
• Distance vs. Time Graphs
Demo!
• Gizmo Lab demo:
Packet Instructions:
Speed Graphs section: p. 7 - end
• Read and highlight important information in
the packet. Work any “problems” you come
across.
• When finished, make sure you have the HW.
• We will go over this section of the packet
before continuing
HW – Juan’s Big Race