牛顿碰撞球的解释与分析

对牛顿碰撞球的常规碰撞形式和混合联珠单球碰撞形式做了理论分析和解释.在常规碰撞时,将悬线(钓鱼线)先悬挂小球一段时间后组装仪器,可克服悬线的拉力.在混合联珠单球碰撞时,根据理论分析,选取大球和小球的质量比为27∶8时,演示效果较好.     

对“验证动量守恒定律”实验的再改进

在"验证动量守恒定律"学生实验中,现行的人教版教材的实验原理图. 设小球1滚下与球2碰撞前的速度为v0,碰撞后球1的速度为v1,球2的速度为v2.若碰撞中动量守恒,则需验证等式m1v0=m1v1+m2v2是否成立.     

小球与均质自由杆碰撞中的瞬心

结合小球与均质自由杆的完全弹性碰撞、完全非弹性碰撞以及一般非弹性碰撞结果,指出球、杆碰撞问题中杆的瞬心的存在,证明了该瞬心位置的唯一性.并从力学原理上对瞬心做出解释.     

以改革实验教学为基础的教学改革

以改革实验教学为基础的教学改革罗明远（江西省永新县禾川中学３４３４００）一、“研究弹性碰撞”实验装置的改革高中物理课本（甲种本）第一册“研究弹性碰撞”实验装置中斜槽末端与支持被碰小球的小支柱等高。入射小球与被碰小球碰撞后，入射小球从斜槽末端水平抛出的...     

用DEM软球模型研究颗粒间的接触力

本文采用 DEM（Discrete Element Method）软球模型来研究颗粒间的碰撞过程,用金属球代替流场中的颗粒,研究这些金属球在平面上的运动。运用DEM软球模型求出碰撞过程中小球所受的瞬时接触力以及碰撞时间,并分析这些参数随颗粒物性以及运动参数的变化规律。计算得出:颗粒间的接触力以及碰撞时间与颗粒的相对速度、碰撞角度以及杨氏模量等参数有关。     

两等质量小球二维碰撞偏转角的讨论

两个质量相等(m1=m2=m)的光滑小球,一个运动,另一个静止,发生非对心碰撞.下面证明:对于完全弹性碰撞,则两球碰后速度之间的夹角等于90°;对于非弹性碰撞,则两球速度之间的夹角小于90°.     

两小球二维碰撞偏转角的再讨论

文[1]讨论了两个等质量小球二维碰撞的偏转角.下面再讨论质量分别为m1和m2的光滑小球,一个运动,另一个静止,发生非对心碰撞,两球碰后速度之间夹角的取值范围.     

基于压电传感器的一维弹性碰撞恢复系数测量系统研究

利用压电传感器、高速数据采集卡设计了小球与平板之间弹性碰撞恢复系数测量系统,并对该测量系统进行了实验验证.该测量系统采用USB-1616HS高速数据采集卡实时捕捉小球与平板之间的碰撞信号,通过对采集到的碰撞波形序列进行处理,获取相邻两次碰撞时间间隔,从而实现对弹性碰撞恢复系数的测量.实验表明,所设计的弹性碰撞恢复系数测量系统具有结构简单、原理清晰、测量精度高的特点.     

《碰撞中的动量守恒》实验中一个易被疏忽的问题

高中物理学生实验《碰撞中的动量守恒》是用两个大小相同但质量不等的小球在斜槽末端发生水平方向上的正碰来验证动量守恒定律。实验巧妙地用小球在碰撞前后飞出的水平距离来代表碰撞前后的水平速度,从而把速度的测量简化为长度的测量。这是基于下述原理:做平抛运动的小球落到地     

碰撞时间的定量计算

在生产实践和日常生活中,碰撞是一种常见的物理现象,在大学力学教材中讨论了把球作为质点的碰撞问题,但对碰撞时间的计算都避而不谈,这是因为问题本身很复杂,涉及的面较广。本文就小球正碰为例导出碰撞时间的计算公式。 一、两球的完全弹性碰撞 设两球的质量各为ml和m2,半径各为R1和 R2,分别由不同的均质材料制成,其杨氏模量和泊松系数各为 E1、vl和 E2、v2。碰撞前的相对速度为vr0,设两球对心正碰。如图1所示。碰撞分两个阶段进行:从碰撞开始后两球心距由于局部变形而逐渐缩短,相对速度逐渐减小到零,此时刻达到了最大压缩状态,这个过程叫…     

多体碰撞实验的设计与讨论

设计了一套简单的多体碰撞实验装置,应用统计原理研究了1个小钢球与N个束缚钢球的碰撞过程,分析了其中一些有趣的现象.     

小球与均质定轴杆的碰撞

从小球与均质定轴杆（质心轴）的碰撞问题出发,讨论了不同类型碰撞所遵循的物理规律,总结了完全非弹性碰撞过程的能量特征．     

碰撞打靶实验中的能量损失及不确定度估算

对碰撞打靶实验中的能量损失,先作理论估算,再通过实验验证.讨论二者不一致时如何获得修正值以及测量值的显著性检验问题.还讨论了实验的不确定度估算问题.得出的结论是碰撞打靶实验过程中的能量损失大部分源于非弹性碰撞,其余主要来自空气阻力.     

一维瞬间碰撞实验研究

在一维瞬态碰撞实验中使用了碰撞过程瞬态数字测量仪测量冲力数据,本文对实验装置及数据的采集、转换和输出进行了介绍,编写了相关的程序对碰撞开始数据进行判断,选择适当的采样周期以提高实验精度,并将实验扩展到牛顿第二定律及研究完全非弹性碰撞.     

Dynamics of a viscous ball rolling down on a rigid staircase

We theoretically investigate the motion of a ball rolling down on a periodical staircase. Our research is restricted in the case of completely inelastic collision when the ball falls down on the surface of the stairs. The ball is accelerated when it rolls cross the edge of the stair, while it is decelerated when it rolls on the horizontal surface due to the rolling friction. The competition between them causes two different regimes according to the parameters of the system. One is the steady moving regime in which the ball keeps moving forever, and the other is the still regime in which the ball finally stops after rolling on a finite number of stairs. The diagram of these two regimes is given in the reduced parameter space. The tendency that smaller scale of the staircase can keep moving on smaller inclined angle is found.     

也谈完全非弹性碰撞和恢复系数

突破了关于完全非弹性碰撞的一种思维定势,引入了两种赝恢复系数。     

A theorem for the distribution functions of hard-sphere fluids

The thermal diffusion factor α_T for the gas mixtures N₂-CO₂, Ar-CO and Ar-NO has been measured as functions of temperature and composition by the two-bulb method. As at least one of the components of the mixture is diatomic or triatomic the thermal diffusion factor is likely to be influenced by inelastic collision. The α_T data have been analysed in terms of the available elastic and inelastic theories. The results show the comparatively small effect of inelastic collision on thermal diffusion. The necessity of using more realistic intermolecular potentials to interpret α_T data has been pointed out.     

Deep inelastic atomic scattering of x rays in liquid neon

An inelastic x-ray scattering (IXS) experiment in liquid neon has been performed in the +/-100 meV exchanged energy range and at exchanged wave numbers, q, comprised between 1 and 16 A(-1). At the highest probed q's a deep inelastic scattering regime is reached where the Ne core electrons, after collision with the x rays, recoil almost freely with an effective mass equal to the Ne atomic mass. IXS in this high q regime is here shown to provide quantitative information on the atomic momentum distribution of liquid Ne, thus supplying a complementary technique to neutron scattering. There are several open problems in quantum and classical liquids which can benefit from this complementarity.     

Experimental investigation of a single-plane automatic balancing mechanism for a rigid rotor

We present an experimental investigation of a single-plane automatic balancer that is fitted to a rigid rotor. Two balls, which are free to travel around a circular race, are used to compensate for the mass imbalance in the plane of the device. The experimental rig possesses both cylindrical and conical rigid body modes and the performance of the automatic balancer is assessed for a variety of different levels of imbalance. A non-planar mathematical model that also includes the observed effect of support anisotropy is developed and numerical simulations are compared with the experimental findings. In the highly supercritical frequency range the balls act to balance the rotor and a good quantitative match is found between the model and the experimental data. However, during the rigid body resonances the dynamics of the ball balancer is highly nonlinear and for this speed range the agreement between theory and experiment is mainly qualitative. Nevertheless, the model is able to successfully reproduce many of the solution types that are found experimentally.     

完全非弹性蹦球的动力学行为

对振动台面上的完全非弹性球的蹦跳行为进行了初步分析.受约化振动加速度的控制，球的运动可以表现出一系列倍周期分岔过程.对几种典型的倍周期运动及分岔情况进行了讨论. 关键词： 蹦球 倍周期分岔 混沌 颗粒物质