Motion Lab: Position vs Time

Purpose:
One of the most effective methods of describing motion is to plot graphs of distance, velocity, and acceleration vs time. From such a graphical representation, it is possible to determine in what direction an object is going, how fast it is moving, how far it traveled, and whether it is speeding up or slowing down. In this experiment, you will use a motion detector to determine this information by plotting a real time graph of your motion as you move across the classroom. An understanding of the graphs of your motion will help you develop an understanding of the concepts of kinematics.

Materials:
Your body, Vernier motion detector, meter stick, chromebook

Procedure:
Download the Vernier Graphical Analysis app from the Chrome Web Store
Connect the Go! Motion motion detector to your chromebook
Launch the Vernier Graphical Analysis app
On the top right, click the view option and select 1 Graph
Place the motion detector so that it points toward an open space a few meters long. Remember, the motion detectors detect the closest object in front of them, including swinging arms and chairs.
Stand about a meter away and have your partner click Collect. Walk slowly away from the detector when you hear it begin to click. Notice what is being graphed. Try walking slowly toward it. How is the graph different? When you are ready, move on to the activities.


Activity 1
Make position vs time graphs for the following situations. Sketch the graphs, drawing only the part of the graph that demonstrates motion you are trying to show. Label the axis with the appropriate number of meters and seconds
Question 1.1: Describe the difference between a graph made by walking slowly and one made by walking quickly.




Question 1.2: Describe the difference between a graph made by walking toward and one made walking away from the motion detector.
Activity 2
Change the data end collection option to manually on the bottom left. Can you produce the following graphs? Draw your best attempt on the graph and describe how you moved in the right column. Include direction, how fast you moved, and if you stopped.

Activity 3
Predict the position-time graph produced when a person starts one meter from the detector, walks away from the detector slowly and steadily for 5 seconds, stops for 5 seconds, then walks toward the detector twice as fast.
Discuss what it would look like with your lab partners. Then draw your prediction on the left graph below.
Test your prediction by moving as described. When you are satisfied with your graph, draw it below on your right.


Question 3.1: Is your prediction the same as your results? If it is not exactly the same, describe how you would move to make a graph that looks like your prediction.




Activity 4
On the bottom left, click the graph tools button and select Add Graph Match and Position.
Move to match the graph displayed. It helps to work as a team. Have everyone take a turn.
Draw a sketch of the graph below and write a description of your motion.










Graphing Recap from Motion Sensor Lab!

Fill in the blanks


The slope of a position vs. time graph represents _________________.



A positive slope indicates _________________.



A negative slope indicates _________________.



A steep slope indicates _________________.



A gradual slope indicates _________________.



Any straight line indicates _________________.



A horizontal slope indicates _________________.



A vertical slope indicates _________________.



Crossing the x-axis indicates _________________.