Measuring distance with an acoustic tape measure 

Measure the linear distance between two XO laptops. 

You need two laptops. Complete the following steps:

1. Launch the Acoustic Tape Measure Activity on one of the XOs.
2. On the first XO in the Acoustic Tape Measure Activity, next to Share with, click Neighborhood.
   
3. On the second XO, go to the Neighborhood View and click the dolphin icon representing the Acoustic Tape Measure Activity on the first XO.
4. On both XOs, click on the "Begin Measuring Distance" button found near the top of the Activity view. It also helps to turn the XO's screens so that they face each other.
   

The first XO sends an audio pulse; the second XO responds with an audio pulse of its own; then both XOs will calculate and display the distance between them in meters. This process repeats until you click on the Stop Measuring Distance button or you exit the Activity.

Tips

• Moving the laptops while they are taking measurements will result in a bad measurement.
• The Activity is accurate to about one centimeter when the laptops are about two meters apart.
• If the "Begin Measuring Distance" button does not activate, try clicking the dolphin Activity icon again on the second XO from the Neighborhood View.
• Atmospheric conditions can impact the accuracy of the measurement; there are overrides to the default settings under the Atmosphere tab.

What am I learning?

You are learning how to estimate distance and lengths and the concept of accuracy. You are also learning that sound travels at a certain rate.

Why is this important?

Measuring and understanding accuracy are important aspects of mathematics, and sound waveforms are a basic concept of physics, both of which help you understand how waves work.