Phone Book Friction Physics
The friction between two objects determines how difficult it will be to slide one object across another. Friction accounts for how your feet move across grass, for example, compared to how an ice skate moves across ice. Scientists use both the coefficient of friction and measurement of normal force to talk about how much friction exists between objects.
In this week's family science activity, families explore properties related to friction by experimenting with phone books (or even pads of paper). Phone books are traditionally large but have very thin paper. When a few pages are interleaved, you may find the books pull apart easily. But the results change as you interleave more and more pages. What observations can you make about friction in this process? How many pages have to be interleaved before the books resist being pulled apart? Does it matter what size books you use?
Put friction to the text with this fun family physics activity:
- Phone Book Friction (science activity at Scientific American)
For another hands-on science project related to this exploration of friction, see: