PS 12A
Names:
Lab 2: Motion x(t) ! v(t) ! a(t)
In this first lab we will look at the motion of some different objects. We are interested in
how we can represent the motion in a variety of ways. This will include using written
descriptions, graphs, and motion maps.
Remember to answer each question fully and include units on all relevant quantities!
Warm-Up:
On the lab table is a battery-operated buggy. Devise a way to measure its velocity to
your best estimate (lowest error). Use the stopwatches and meter sticks to help you.
Graph this motion on the graph paper provided.
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Describe the motion of the buggy.
Create a motion map (Arrows that represent the displacement and velocity of the
motion)
Assigning error: What is the error in your time measurements? What is the error
in your displacement measurements? Represent these on your graph.
What is the average speed of the buggy? How did you find this?
What is the maximum and minimum possible speeds of the buggy?
Create velocity vs. time graphs and acceleration vs. time graphs for the buggy’s
motion
Part I: Position vs. Time
In this section consider the following plot of position versus time. You will determine how
to recreate that plot by walking in front of the motion detector.
(a) Describe the motion (i.e., “I stood still for a second then …”)
(b) What is the total displacement traveled in the above plot?
(c) What is the total distance traveled in the above plot?
(d) In what time range did the person move the fastest? How fast did he move and in
what direction? Explain your answer.
(e) Create corresponding velocity vs. time and acceleration vs. time graphs
(f) Using the motion sensor recreate the above position vs. time plot. Show your TA.
Part II: Velocity vs. Time
In this section, consider the following plot of velocity versus time. You will determine
how to recreate the plot by walking in front of the motion detector.
(a) Describe the motion (i.e., “I stood still for a second, then…”)
(b) What is the total distance traveled in the above plot?
(c) What is the total displacement in the above plot?
(d) In what time range did the person move the fastest? How fast did she move and
in what direction? Explain your answer.
(e) Create corresponding velocity vs. time and acceleration vs. time graph
(f) Using the motion sensor recreate the above velocity vs. time plot. Show your TA
Part III: Acceleration vs. Time
In this section, consider the following plot of acceleration versus time. You will
determine how to recreate the plot by walking in front of the motion detector.
(a) Describe the motion you underwent (i.e., “I stood still for a second, then…”)
(b) What is the total displacement in the above plot? Do you have all the info
needed?
(c) What is the total distance traveled in the above plot?
(d) In what time range did the person move the fastest? How fast did she move and
in what direction? Explain your answer.
(e) Recreate the Acceleration vs. time plot. Show your TA.
(f) Using the motion sensor recreate the Acceleration vs. time plot. If it helps there is
a program on the desktop called Graphs and Tracks that may make things
easier.
Part IV: Describing more interesting motion
On your bench is an example of an object with more interesting motion. After gaining
an initial qualitative understanding of the object’s motion, use the equipment on your
desk (cameras, sensors, rulers, etc.) to make quantitative statements about the motion.
This includes, but is not limited to, motion diagrams and graphs of position, velocity and
acceleration. Make note of any interesting features of the motion as well. You’ll be
given a large tablet of paper for use in a short presentation to the class at the end of the
lab period. Please draw on the paper large enough so that everyone can see. During
the presentation,
• Tell us about your object
• Give a short description of the motion
• Predict what the displacement, velocity, and acceleration graphs
• Analyze the motion
• Describe any difficulties that your group encountered