The Transportation Problem

 During the summer, when @whowe67 and I met to plan the IPC year, one of our original ideas was to do the force and motion unit with mousetrap car kits.  Making those cars would be a part of a STEM curriculum as they tried to solve the challenge of putting the kit together to make a car.  But as we continued to talk about what we wanted the year to look like, we realized that giving students those kits would be too teacher-directed, and discarded the idea.

However, we kept the idea of doing some sort of transportation design on the island.  After many brainstorming sessions, we chose parameters for the unit.  The devices would have to travel 10 meters, but no further (because otherwise they would fall off a cliff on the island).  And it would have to carry a cup of water without spilling it.  The students weren’t allowed to seal off the cup to prevent the water from getting out.

The cup of water was a nice call-back to their first challenge – purifying the water.  Also, many of them used their renewable energy sources from the previous power unit as a way to provide power to their devices.  One of the good things about integrating the whole year into a consistent story line is that all the units have significance and can be relevant for a future problem. 

I had eliminated batteries as a source of potential energy for their devices, so the students were left with using either gravitational energy or elastic energy.  They quickly realized that gravity could give them a great deal of power, but because going over 10 meters was a design failure, it didn’t offer a lot of control over their transport method.  During their presentations, many groups explained why they decided to use elastic potential energy, and I was happy to see the detailed thought process that they used to evaluate the two sources of energy.

My students found a variety of ways to solve the problem of transporting the water, but many of them discovered the mousetrap cars via YouTube. 

With the parameters we added to the problem, the students couldn’t copy what they found on YouTube directly.  For one thing, the car had to be stable enough to carry the cup without spilling, and for another, the platform had to be big enough to hold the cup.

During the presentations, I was thrilled to hear the students talking about how they had to change the design from the original, the problems they encountered, and the reasons why things weren’t working.  The depth of critical thinking they demonstrated was impressive.  While the basics function of the mousetrap car remained the same, my students found many solutions to the problem of carrying the cup.  They also made use of a wide variety of materials, many of them salvaged from their kitchens and garages.

If we had kept our original idea of handing everyone a kit, then I wouldn’t have seen so much creativity in the students’ final presentations.