Expert: Spaceman - 10/18/2007

Question
What factors affect domino phnomena, In other words, What are the justifcations for the following action:
when you line up dominos, and hit the first one, the rest fall.

Are there any formulas or equations related to that

Thanks

Answer
Hello MHS:

Thanks for your question!

The physics of a row of toppling dominoes:

(Some web extracts)

The forces between the falling dominoes are analyzed and with this by 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.

The energy in the next falling domino doesn't just come from the energy transferred from the domino that hits it. If that were the case, then the cascade would eventually stop. But each standing domino also contains it's own potential energy, which was given to it by it's being lifted into an unstable equilibrium by whoever set them up. This will most probably be enough to keep the cascade going for eternity.

The kinetic energy of the striking domino only has to have enough force to overcome the threshhold energy that trips the domino out of it's vertical unstable equilibrium. How much energy comes from that domino falling over is a functioon of the geometry of the domino and the strength of the local gravitational field.

I hope this info iss of some help.

Cheers,
Spaceman