The Domino Effect
  The physics of a row of toppling dominoes is discussed. In particular the forces between the falling dominoes are analyzed and with this knowledge, the effect of friction has been incorporated. A set of limiting situations is discussed in detail, such as the limit of thin dominoes, which allows a full and explicit analytical solution. The propagation speed of the domino effect is calculated for various spatial separations. Also a formula is given, which gives explicitly the main dependence of the speed as function of the domino width, height and interspacing. 
J.M.J. van Leeuwen