A Simple Alternative to the Phone Book Friction Demonstration

In this paper we describe a simple alternative to the telephone book friction experiment, a classic demonstration where a small force (generated for example by the bending of the outer pages) is amplified by the large number of surfaces in contact, resulting in a huge maximum static friction force that has to be counterbalanced in order to separate the books. The aim of our experiment is to illustrate the friction force in a dramatic way and to simplify the tedious job of interleaving a large number of book pages, by using the minimum number of sheets necessary to sustain the weight of a person using the normal force produced by their fingers.