Position and velocity over time
What students will learn
- Connect real movement to position and velocity graphs
- Predict the graph a movement will make before seeing it
What you'll need
- Distance sensor
- About 3 meters of clear floor
- Tape to mark start lines
Setup
Place the distance sensor at chest height on a desk, aimed down a clear walking lane. Mark a start line about half a meter from the sensor and another at 3 meters.
What students do
- One student stands on the far line while the class watches the live graph.
- Ask the walker to move so the position graph makes a hill, then a flat line, then a steep drop.
- Swap walkers. Give each a secret target graph the class has drawn.
- The class guesses the target from the walk. The graph settles the argument.
- Switch the display to velocity and repeat one walk. Talk about why it looks so different.
What to expect
Loud, fast rounds of guessing, and then the quiet click when students realize a flat position line means standing still, not lying down. The velocity view usually surprises everyone the first time.
Teaching notes
This is the single best first-day activity with a distance sensor. Resist explaining before the first walk; let the graph do the teaching.