Away and Back

Track the motion of a student using a motion sensor and view graphs of their position and velocity.

Setup:

Plug the motion sensor into the Pasco interface and connect the interface to the computer. Open the Pasco data collection software and setup a graph of position vs. time and velocity vs. time. Place the motion sensor at the edge of the table oriented towards a person. Press record in the data collection software and have the person walk away from and towards the sensor. The graphs will populate. Press stop to end data collection.

Notes:

Make sure the motion sensor is on the setting for a person walking. (There is a switch on the unit.)

The sensor is not accurate at distances very close to it (< 1m). For best results use distances of 1 to 8 meters.

Courses Used In:

• PHY 10111

• PHY 10310

• PHY 10410

• PHY 30210

Discussion and Polling Questions:

• If the student only goes in one direction, can the slope of the position vs. time graph ever change sign? Can the slope of the velocity vs. time graph?

  • • How does this change if you were going in both?

• What does the slope of each graph represent?

• How does average velocity/acceleration appear on a graph?

• Can your instantaneous velocity be higher than your average? Can it be lower?

• Let's say your average velocity was higher than some speed limit. Could you have been going slower than this limit the whole time?

  • • Did anyone ever need to measure velocity directly to know you were speeding?

Equipment Needed:

• Demo Computer or Laptop with Pasco Software

• Pasco Interface

• Motion Sensor