touch the floor

In this paper,another way is used to prove that the chair stands steadily by moving a little,which is to use the angle between the legs of the chair and the pertinent diagonal to judge whether the legs of the chair touch the floor.

关于椅子能否在地面上放稳的问题,以前建模的方法是用椅子脚与地面的距离来度量椅脚是否着地。

Through con- trolling the time difference of collapse, the chimney was controlled to collapse on a collapsing workshop, the vi- bration test showed that the surface vibration caused by the chimney collapsed in such way is remarkably low- ered than that in ordinary way.

通过时差控制，使烟囱倒塌在尚未完全着地的厂房上，振动测试表明 １００ ｍ高烟囱的着地振动大大小于预计着地振动。

The result shows that there exist great relation between landing angle and lose of horizontal speed.

结论 :着地角的大小直接影响重心移过支撑点即前支撑时间的长短 ,从而影响水平速度的损失率 ,也是影响每一跳水平、垂直速度分配的重要因