Inside SFS

8th Grade Engineering Design Challenge: Mousetrap Cars

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By Eugene Stampley, 7th & 8th Grade Science Teacher

8th Grade scientists are finishing up their latest STEM Design Challenge: mousetrap cars! In this challenge, using the Engineering Design Process, teams of three students collaborate to build a basic mousetrap car prototype that uses the classic set-up of string connected to the lever arm to rotate the axle.

In the first stage, each team received the same recycled materials and instructions for building, with the goal of having their car travel exactly five meters. They were required to do a good amount of background research related to speed, acceleration, velocity, energy (potential and kinetic), and Newton’s three Laws of Motion.  

Once the cars were prototyped, we had what I call Epic Failure Day. On that day, we tested the cars with the expectation that most or all will not be able to travel the full five meters. Anything that meets the standards, we celebrate, of course, but if a car doesn’t, that’s fine - that just means it’s time for students to brainstorm and figure out what modifications they’ll need to make for the next prototype.

Each group brainstormed and selected one modification they’d like to make to improve their car’s ability to travel five meters. They were only able to make one change per prototype, to really isolate what the variable was, and to identify which modification was the most effective. They conducted more research to support their modification, and then were able to build and rebuild as many times as they were able to fully plan and test each idea. For instance, one group changed the wheel material from styrofoam to CDs to reduce friction, and another measured the wheels and predicted how many revolutions the wheels would need to travel five meters.

Our final testing phase will be this week - please stop by the 7th & 8th Grade Science Room to see students’ fabulous work!

Posted January 29, 2019