In fact, it is only necessary to calculate the time from the fall of the first block to the contact with the second block, and the rest is exactly the same as this, which should be related to the height and spacing of dominoes; At the same time, I think it has something to do with the initial kinetic energy of the first piece (that is, the initial speed of falling), but this influence should be small, and the attenuation between multiple pieces of contact should not have much influence on the overall speed, so I think it can be ignored here (assuming a large number of dominoes).

The specific quantification should be the process of finding the center of gravity of the domino from the initial point (the bottom edge should touch the ground, and the domino on the other side can just stand upright) to the initial point when it touches the second block, and there is a process in which the first block transfers energy to the second block to the initial point. The physical analysis process of this process feels complicated.

It is suggested to divide the time by the number of blocks to calculate the dumping speed. For example, how long it takes for 1000 dominoes to start and end, and the dumping speed can be calculated. The larger the denominator, the more accurate it is.

If the direction is determined from the beginning, there is no need to calculate it.