CMS students see science in action during 15th annual mousetrap car rally
December 21, 2011
Slowly but steadily, Tanner Hampton's mousetrap car crept away from the starting line Tuesday morning.
His car didn't make it to the other end of the Craig Middle School gym, where he and other eighth-graders participated in the 15th annual mousetrap car rally.
But, the 12 hours he spent on the project was far from a loss. If nothing else, it helped him understand how some of the simplest machines work.
"I learned how friction has a lot to do with how things move and operate," he said, examining his car after its run across the polished hardwood.
The rally was the culminating activity in a physics unit, said Sandy Sorensen, a CMS seventh- and eighth-grade science teacher.
To construct a mousetrap car, students had to apply their new-found knowledge of simple machines, specifically levers, wheels and axles.
The concept behind the contraption is simple: attach a lever to the spring in the center of a mousetrap, tie a string to it, then wrap the other end of the string around the car's back axle.
When the lever is released, the spring pulls the lever forward, thereby unwinding the string and turning the axle.
Mousetraps weren't the only household item conscripted for the project. Many cars sported wheels made of cast-off vinyl records and CDs.
"They build it all themselves," Sorensen said, although teachers offered help if needed.
"(Students) have to be resourceful (and) find all those parts and figure out how to put them together," she said.
They got creative in other ways, too.
The words "Rat Rod" were scrawled across the top of one car. On the back of the car, it read "Eat my dust."
Getting the hang of making the cars go without the aid of a push or a motor is harder than it looks.
"I'm trying to get this string to wrap around the axle," eighth-grader Ian Day said as he bent intently over his car.
He put careful consideration into his project. He chose vinyl records for the tires because they would get more distance with a single turn, he said.
"The wood for this part is lightweight enough to compensate for the weight of the records," he said, pointing to the frame between the wheels that held the mousetrap.
Now, if he could only get that string to cooperate …
Sorensen watched Day's car a few minutes later as it crawled forward.
"This isn't going to count," she said as she gently tugged on the string as it unwound slowly from the axle. "I'm just going to see if I can keep it going."
Students are evaluated on their cars' performance, Sorensen said, yet the project's importance goes beyond the grade. She believes it can get children interested in science when more traditional methods cannot.
One student who doesn't do particularly well with worksheets and the like "was the first one to hand in his car," she said.
"This was his thing," she said. "He loved it."