Assume Bro 用0.9999..c 去推個個塊板 而assume個Bro 同個pivot point 既distance 係 b
當個pressure wave 傳到去另一邊同樣position (distance = 2b)既時候 佢無可能再向右propagate 因為當 distance from the pivot point to RHS >b 既時候係呢個material point take 既energy 就會係infinite 所以pressure wave 永遠唔會propagate 到去 You 到