Myth confirmed – book friction!

In celebration of the Mythbusters tour of Australia this week, we thought we’d put to the test one of the simple experiments featured on the show. Back in 2008 the Mythbusters team demonstrated the power of friction using a couple of phone books. We set up our own version with a pair of debited books.

1. We grabbed a pair of debited books destined for recycling, enabling them to contribute to library science one more time prior to retirement.Book friction 1
2. Placing them next to each other, we interfiled the pages by fanning, similar to shuffling a deck of cards. book friction 2

3. We ensured every page, or close to every page, was interfiled. Book friction 3

4. The books are totally interfiled. You can already feel the power of science radiating from them.Book friction 5

5. Benjamin and Hannah each grabbed a book by the spine.Book friction 6

6. Check out the tug-of-war that ensues:


So what’s actually happening here?

Pages of books are not perfectly smooth, like all surfaces there are minute imperfections. Rubbing two surfaces together produces friction due to these tiny imperfections. In this case we are demonstrating static friction, which causes two bodies resistant to sliding past each other. A pair of single pages will not generate much friction at all, however the combined total of hundreds of pages interlocked will create huge amounts of friction. The books are impossible to pull apart!
If you want to see the Mythbusters version they used two phone books, which produced so much friction they could tow a car with it!

2 thoughts on “Myth confirmed – book friction!

  1. I just have one doubt

    If you make the books vertical.. then shouldn’t friction disappear? cause the normal forces of pages on each other disappear?

  2. Great question Mahesh! Friction is not reliant upon gravity, however gravity does assist in stopping the bottom book flop open when held vertically. However we repeated the experiment vertically with the same result, the books were impossible to pull apart.

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