Abstract:

Based on the conservation law of momentum and the conservation law of mechanical energy，the problem about the collision times between blocks is discussed in depth. Particularly，when the ratio of the mass between two blocks is nonnegative integer power of 100，collision times are just the same as the first few digits of circular constant. The velocity phase diagram is used to describe the collision process intuitively，and then the above

interesting result is explained by combining theoretical derivation.

Key words: conservation of momentum, conservation of mechanical energy, collision times, velocity phase diagram, circular constant