Laboratory 1 – Position Graphs
Stephanie Burba
Partners: Matthew, Mark, Luke, John
August 24, 2009
Summary
My partners and I walked towards and away from a motion detector to generate several
different position graphs. These graphs sloped up and down at different rates depending on how
we moved. From these graphs, it can be seen that the slope of the graph tells how the person is
moving: positive (negative) slope means moving away (towards) the detector, and the steepness
of the slope indicates the speed.
Experiment
For the first activity of this experiment we used DataStudio and an ultrasonic motion
sensor to create several different position graphs. The graphs were created by a person holding a
book, walking away from or towards the motion detector at different rates. First we did away,
slow then fast, then towards. For the second activity a graph was created of a person walking
away from the detector at a slow rate, stopping for a few seconds, and then continuing backwards
at a faster rate. In the third activity we tried to match an already created graph.
Results
This first graph contains several runs where a person moved away from the detector at
different speeds, and then walked toward it. The different motions have different results for the
sign and slope of the graph.
The second graph was created by a person walking at a slow pace away from the
detector, then standing still, and then walking at a faster speed then the first.
For the third graph, we tried to move to make our motion (purple line) match the given
graph (red line). First, I stood still for two seconds, then moved away quickly for two seconds,
then stopped for two seconds, then moved back toward the detector not as fast.
Conclusions
The main physic principle used during this lab was motion at a constant speed and the
position graphs generated because of this movement. The properties of these graphs indicate
what type of movement was taking place. The horizontal distance from the x-axis represents the
distance traveled and the vertical distance from axis represents the time it took to reach that
distance. The steepness of the slope of a line represents the how fast or slow the person was
traveling. The steeper the slope, the faster the person paced. The direction of the slope identifies
whether the person was walking away or towards the motion detector. If the slope was
decreasing the person was walking towards the motion detector, if the slope was increasing or
positive the person was walking away from the motion detector. This makes sense, because the
motion detector is our point of reference, and therefore is located on y coordinates at 0. If the
slope was zero, or the graph contained a horizontal line, the person was standing still.