跳远和跳高腾空过程中的合理动作是比较复杂的。动作的技术原理除了要应用动量的传递和守恒原理以外,还应该用到转动力学的原理。例如,走步式跳远的空中走步动作,可以抵抗起跳时身体重心获得的向前转动倾向,使身体保持正直、平衡;俯卧式跳高为使人体在空中旋转过杆,必须在踏跳时有一定的偏心推力,而且过杆时要迅速收拢摆动腿,同侧手臂要往上抬,以造成人体绕纵轴迅速转动等等,这些合理动作无不要应用转动力学的有关知识来解释。一、空中转动与力矩“转动”作为一个生活中的概念,人们是十分熟悉的。工厂中机床运转,田野上拖拉机车轮滚滚,家庭里时钟走动,乃至我们每天开门、关门等等,都为我们认识转动提供了生动具体的形 The proper actions in the process of long jump and high jump are complicated. In addition to applying the principle of momentum transfer and conservation, the technical principle of motion should also apply the principles of dynamics. For example, a step-by-step airborne walking action can resist the forward turning tendencies obtained when the body’s center of gravity is taken off to maintain the body’s straightness and balance; the prone horizontal jump is such that when the human body rotates in the air, it has to be A certain eccentric thrust, and when the rod should be quickly gathered swing legs, the same side of the arm to be lifted to cause the body to turn around the vertical axis, etc., these reasonable actions do not apply the transfer of dynamic knowledge to explain. One, the air rotation and torque “rotation” as a concept in life, people are very familiar with. In the factory, the machine tool is running, the tractor wheel is rolling in the field, the clock in the family moves, and even we open the door every day, close the door, and so on, all providing a vivid and concrete shape for us to know the rotation.