Have you ever wondered how automatic doors at grocery stores know when to open? There is a sensor over the door that detects objects, such as a person walking up to the door.

The Motion Detector that you will use in this activity can also do this. The Motion Detector works by sending out a signal and then measuring how long it takes for reflections to return to the sensor. Based on the amount of time it takes the signal to bounce back, the data-collection software is able to calculate the position of the object.


  • Explore the different lines and curves produced by moving in front of the Motion Detector.
  • Learn to write detailed steps for creating an M or W shape on the graph.
  • Match different letter and designs drawn on the graph.