Making Measurements
Using a Graph to Measure

You need to make some measurements. How can the motion probe and graph help you?

To make measurements, you need numbers, so now it is time to focus on the axes of the graph. You need to find out what they tell you.

Go on to the next page.

The X-Axis: Time
The motion probe measures time on the horizontal axis, also known as the X-axis. To practice measuring time, you will measure the time between two jumps.

Record this motion in front of the probe: 
• Stand still and wait awhile.
• Make a small jump toward or away from the probe, and wait awhile again. 
• Then jump back and stand still.

Use your graph to measure the time between the jumps. You may want to use the Label tool on the right of the graph to help you read the time values.

Submit the graph and the answer to the questions below.










The length of time between two events is called a duration. Think about how you found the duration between your two jumps.





How long was the time between the two jumps? How did you get your answer? Write a rule for finding the duration between two events.
The Y-Axis: Position

The motion probe measures position in meters on the vertical axis, also known as the Y-axis.

Use the probe and graph to answer the questions below. You may use the Label tool to help you read values on the graph.

Experiment with the motion probe to find its range — its shortest and longest position measurements.

Submit the answers to the questions when you are done.

















What is closest position measurement you can make in meters? -2.0 -1.5 -1.0 -0.5 0 0.5 1.0 1.5 2.0 2.5 What is the farthest position that the probe can measure in meters? (To test this, please keep the probe on the desk and use only space that is easily available to you.) -2.0 -1.5 -1.0 -0.5 0 0.5 1.0 1.5 2.0 2.5 more than 2.5 Describe how you found the closest and farthest position measurement.
Finding Zero
For this step, your teacher will give you a 1-meter measure.

Use the graph and the 1-meter measure to find out approximately how far position = zero is from the probe in meters.











What number is the closest to the distance from zero to the probe in meters? 0.25 meters 0.5 meters 0.75 meters 1.0 meters 1.25 meters 1.5 meters Describe what you did to find the distance from zero to the probe. How long were each of your team members’ giant steps? Describe how you measured these distances.
Measuring Giant Steps

Use the probe and graph to measure the distance of one giant step . You may use the Label tool to the right of the graph to help you.

Measure the giant step distance of all team members, but submit one graph that demonstrates how you measured this distance. Then answer the question below.










Position and Distance
For the questions below find the distance between the two positions. You may use the graph to help you.



















What is the distance between position -0.5 to -0.25 meters? What is the distance between position 0.5 to -0.5 meters? What is the distance between position 0.5 to 1.25 meters? Write a “rule” for finding the distance between two positions?
A Rule for Distance
Skip this page until you have discussed the previous page. Return here after class discussion.




After class discussion, write a "rule" for finding the distance between any two positions?
Measuring Speed
How fast can you walk heel-to-toe, heel-to-toe? Can you find out with the motion probe?

So far, you have measured distance and time. Can you measure speed? Remember that speed is distance divided by the time it took to go that distance.

Create a graph of heel-to-toe walking. Place labels on your graph to help you make measurments and explain how you got your measurements.

Submit the graph and the answer to the question below.









What is the speed of the heel-to-toe walking shown on your graph? How did you find your answer?
The End
Congratulations! You made three measurements with the motion probe and motion graph: 
• The distance of a giant step.
• The time between two jumps. 
• The speed of heel-to-toe walking.
Good job!

You may now close this activity. Your work will be saved automacally.