Inside SFS

Using (the) Force: Second Grade’s Simple Machines

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2nd Grade, Science

Second Graders started a new inquiry-based unit, experimenting with simple machines to better understand how they make work easier

By CJ Logel, Second Grade Teacher

Second Grade has started one of our favorite Project Time units, Simple Machines! For those who could use a reminder from their own school days, simple machines are mechanical devices that change the magnitude or direction of a force. They come in six major categories: levers, incline planes, wheels and axles, screws, pulleys, and wedges.

As the Second Graders can now tell you, humans use simple machines to make work easier. We can define work being “easier” as needing to use less force to accomplish something. We start by exploring the concept of force, and experiment in depth with each type of simple machine. The overarching goal is for students to demonstrate how using each machine results in using less force to move or do things.

Click here for a little more information about what simple machines are and how they work!

This summer, I was lucky enough to do some professional development coursework at the Academy of Sciences. This gave me the chance to incorporate some great new inquiry-based aspects to the unit this year, in which the class develops research questions and then designs experiments to answer those questions.

One example was this past week’s question: Do some things fall faster than others? Second Graders worked in pairs to conduct an experiment, dropping two objects from the same height and at the same time (a “fair test”), then recording which object hit the ground first.


After the pairs collected their results, we tallied the class results and examined the data to try to understand what it showed us.

Students noticed that many objects landed at the same time (i.e., fell at the same rate), except for the feather, which was consistently an outlier. The plastic bear, on the other hand, landed first every time; students hypothesized that this was because the feather moved from side to side as it fell (picking up resistance), whereas the bear fell straight down. Some students started to wonder: what does this have to do with how birds fly, and how having feathers that fall slowly might be advantageous in flight - it seems like they’re almost ready for our next Project Time unit on birds.

After some more experimentation, our unit will culminate with a group fort-building project, incorporating what students have learned to construct forts containing each of the six types of simple machines. Stop by Second Grade in a few weeks…and may (the) force be with you!

Posted January 15, 2019