By careful analysis, we found that the main reason is friction between bear and verticalside.
针对这一问题进行了深入分析，发现轴承与砂轮架端面之间的磨擦是重要原因。
2
Based on the law of momentum conservation, the mathematics patterns of front collision and verticalside collision of motorcycles and motor vehicles are developed.
根据动量守恒定律，建立了摩托车与汽车正面碰撞及直角侧面碰撞的数学模型。
3
In the actual research, the objects are usually circular cylinder, and other objects are mainly square cylinder and rectangular cylinders which have verticalside walls.