In this lab, students look at various factors that affect the frictional force between two objects:
-Type of surface
-Mass of objects
-Type of friction
-Block of wood (I used a 1ft piece of sanded 2x4)
-Some method of attaching the scale to the block (to pull it)
-A piece of sandpaper
-An object with roughly 2-3x the mass of the block (heavy book?)
I use a digital force gauge, connected to my computer, in conjunction with a camera, to collect the data from the lab as a CLASS, so everyone's working from the same data set. This could also be done with an analog spring scale, and a camera. It just depends on whether you want them to collect their OWN data or not.
An answer key is included. The data is specific to the lab, as I completed it in my classroom, but it gives you an idea of what the results SHOULD look like, relative to the factors being tested in the lab.
I also have a video of the lab available, should materials not be available, students need to make up the lab, or you're a teacher that would like to see how the lab works.
I use this lab in my 7th grade classroom, but it would work equally well in a higher level classroom, particularly, if students are pushed farther when it comes to defending answers with data from the lab, or creating more complex explanations of the results.