Try your hand at making your very own Mini Miss Phone Friction.

What to do:

1. You hold one of the telephone directories and give the other to your friend.
2. Using a table to rest the directories on, lay down one of the pages of your directory and then get your friend to do the same. Taking turns, make sure you lay down the pages one on top of the other.
3. Continue for all the pages in the directories. This will take some time, but keep going as the better you do this part, the better the experiment will be.
4. All the pages of the directories should now be overlapped.
5. With you holding the spine of one of the directories, and your friend holding the spine of the other, lift the books off the table. Now try and pull the directories apart - as if you were playing tug-of-war.
6. Try not to wiggle the books - just pull. You should find that the directories do NOT pull apart, no matter how hard you try!

Here we're seeing friction in action. Friction makes things harder to move. The rougher things are and the more things touch, then the more friction there is. Here, the pages of the directories are very rough so they have a lot of friction. And with so many of the pages overlapped the amount of friction is huge!
So, as you try to pull the books apart, the friction between the pages stops the pages sliding past each other and the books stay firmly together.