Teacher Talk: Science – Car Pull

January 29, 2021

There is an old proverb which goes something like this: “Tell me and I will forget, show me and I may remember, involve me and I will understand”. This has been a tough year for having students do the most important part of any science lesson…the lab. This is the part of science that really has students get involved in an idea for understanding. Due to COVID-19, many labs which include students huddling together for long periods of time to make observations or measurements have not been possible. But this year’s 6th graders were involved in a lab a few weeks ago which adds them to an elite group of people which has been growing here at MCS for a decade now. This group is, of course, those people who have towed my automobile up a hill (with and without a pulley system) to understand the mechanical advantage. This tradition began with the truck that I first drove to Vermont from Tennessee — my 2006 Nissan Titan. Next, we towed the much less substantial Suzuki Sx4, and finally my current ride, a Honda Pilot. Students in this lab determine the force needed to pull the car using a simple unit: how many people does it take to pull the car. We measure distance using steps. With these units defined, we can employ the formula Work = Force x Distance to explore the mechanical advantage with and without the pulley system. Students were even able to calculate the mechanical advantage of the pulley system by observing how much less force, and how much more distance, was required once the pulley system was attached. So if you ever get your car stuck in the snow, just be sure you have a long rope, a few pulleys, and a 6th grader.

Mark Pendergrass

Middle School Science Teacher

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