Preschool children know that it is easier to walk up a slide in parts where it is less steep or that objects sliding down may come to rest where the slide is less steep. They know what clothes let them move fastest down a playground slide and may have learned that this is related to friction. They are also likely to have discovered the effects of rain on the slide, and possibly also of sand. But there is more to discover and learn about friction than the term itself and the differences between different materials.
Experimenting on a playground slide can be combined with more systematic investigations of wooden blocks covered in different fabric. Some of the investigations by middle school students are shown to the right.
Read more about their investigation in Motion on an inclined plane and the nature of science, in Physics Education, 49, 180 2014, with a Video abstract. (Manuscript copy)