This is a great lab for middle school/high school students to complete. I use the lab as the third in a series of friction labs. I do this one last in the series after we have learned to calculate pressure and ways to change pressure.
Students copy the different parts of the investigation onto their own papers and color code each section. I find this makes it easier to quickly glance for needed information as I move around the room as well as ease in grading. It is also an excellent review of the scientific method as we move through asking a question, forming a hypothesis, copying a procedure, collecting and analyzing data, drawing 2 graphs, and writing an in-depth conclusion.
Doing this activity makes it easy to incorporate a writing activity into your science lesson.
I have also created a grading rubric (included with the lesson plans for this activity) that makes it very easy to grade this comprehensive lab activity. Each section has been assigned different values, with the graphs and written conclusion worth more points than the section where they simply copy the procedure.
The lesson plan with detailed set-up instructions and grading rubric can be found here
Will differences in surface area affect friction forces? by Lauren B. McVey is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License