Using motion dectectors to explore speed and velocity

I used the Go! Motion Vernier probes this week to teach about speed.  Historically students have struggled with this idea and the graphing as freaked them out.  Not this year.  I borrowed a motion detector from a colleague and set it up in the front of my room.

The labs that Vernier suggested were powerful teaching tools and my kids "got" it.  Right off the bat and better than any other year I can imagine.

It was powerful to project the graphs onto my Smart Board.  These huge graphs made getting everyone at the same place at the same time pretty easy.  I loaded a blank graph onto the SB and used 2 students of very different heights to slowly walk a distance I had pre-measured.  This way they figured out how the detector worked and got into the spirit of the activity.

Next I projected a graph onto the board and they took one minute to plan how they would walk so that the line the motion detector plotted would match the one I displayed.  Discussion between shoulder partners was abuzz with tons of ideas.

When they started to walk, it only took a couple of student tries for them figure out what worked and what didn't work.  Once they had the idea, we worked on strategies for getting a closer and closer match.  Without even realizing it, the students learned that to have a flat line on the graph you needed to stop moving; to get the line to have a steeper slope they needed to speed up and so on.

One of my perennial science ba-humbug kids said to me..."hey I actually get this."

We added on just a bit....I asked them to use the Smart Board pen and draw a prediction line of what would happen to graph if they walked toward the detector instead of away.  Out of the 4 classes, 3 classes correctly predicted.  All classes "got it" before 10 seconds had passed.

Here is a perfect case where the lesson wasn't about the technology, but what the technology allowed us to discover about the concept.  It's why I love technology and can't imagine how I'd teach some concepts nearly as well without using it.  I wouldn't want to go back to the pre-SmartBoard days or not have access to probeware. 

I'm just starting to learn about probes...now I have 2 under my belt...this motion one and the temperature probe.  Maybe I can get a grant to buy a force one or the UVA or UVB dectector.  this is engaging science...it is science where we learn by doing not just by reading.  It makes the textbook stuff come alive and they really comprehend what they read.

Comments

[Donna]

Can I add something about motion detectors?

A motion detector is a device that contains a physical mechanism or electronic sensor that quantifies motion that can be either integrated with or connected to other devices that alert the user of the presence of a moving object within the field of view.

An electronic motion detector contains a motion sensor that transforms the detection of motion into an electric signal. This can be achieved by measuring optical or acoustical changes in the field of view.

A motion detector may be connected to a burglar alarm that is used to alert the home owner or security service after it detects motion.

An occupancy sensor is a motion detector that is integrated with a timing device. It senses when motion has stopped for a specified time period in order to trigger a light extinguishing signal. These devices prevent illumination of unoccupied spaces like public toilets.