Calculating and
Graphing Speed
Distance, Time and Speed
• Distance : the amount of space BETWEEN 2
objects; symbol = d
• Time : an interval having a beginning and an end;
symbol = t
• Speed: the distance an object travels divided by
the time it takes; symbol = v
• Constant speed: the same distance is traveled
every second or time interval
Calculating Speed
v = speed of an object
d = distance traveled (m or km)
t = time traveled (sec, min or hr)
Units for Speed: m/sec -or- km/hr
1.
2.
3.
4.
Solve these problems
If a car travels 4.50 m in 2.58
seconds, what is its average speed?
Convert the speed in question #1
to miles per hour.
If a car travels 65 km at 23 km/hr,
how long does it take?
A snake moves at 4.1 m/sec for 5.2
seconds. How far did the snake
travel?
Challenge Question:
• A pitch takes 0.420 seconds to reach home
plate. If the pitch is traveling at 98.5 miles
per hour, what is the distance from the
pitcher to home plate in feet?
Interpreting Graphs
The purpose of a graph is to show a RELATIONSHIP
between 2 variables
1. Positive Relationships:
• One variable increases, so does the other
• Or one variable decreases, so does the other.
2. Negative or Inverse Relationships:
• One variable increases, the other decreases
• Or one variable decreases the other increases.
Positive Relationships
Negative Relationships
Line of Best Fit
• Line of Best Fit: Straight line drawn through linear
data.
• The line does not necessarily connect the data
points but is drawn through the majority of points,
with an equal number of points above and below
the line.
MOTION GRAPHS
Graphs dealing with motion will have the
following variables on their X and Y axis:
• Distance/Position
• Time
• Speed
• Acceleration
• Distance and time will be used to
calculate speed and/or acceleration
Constant Speed
• Position vs. Time graphs will have a straight line
when the object is traveling at a constant speed.
Slope = Speed
Changing Speed
• A position vs. time graph will have a
curve when the object is traveling at a
changing speed, steepness of the curve
will indicate just how fast object is
changing speed.
Speed-Time Graphs for
Acceleration
• Rate of change in
an object’s speed
• Slope =
Acceleration
• When you plot
speed vs. time,
you now have the
acceleration of an
object.
Distance from Speed vs. Time
Graph
• Distance is equal to speed x time
• The area of a graph represents speed x
time
• Therefore the area below the line of best
fit is the distance traveled