关于测定转动惯量的几个实验及其分析 大学论文.doc

本科毕业论文（设计） 题　　目 关于测定转动惯量的几个实验设计及其分析 关于测定转动惯量的几个实验设计及其分析 摘要：关于测定转动惯量的实验方案，实验室常用动力法，利用转动定理，通过对刚体转动时所受力矩和角加速度的测量求得待测转动惯量。实验室测刚体转动惯量用到的核心仪器有，带小滑轮的转动惯量仪、自动计数仪。其中转动惯量仪转动系统的转动惯量已知。在实验中，小滑轮的转动惯量和缠绕系统转轴并连接砝码的细绳质量是没有单独考虑的。另外，转轴和支架之间、转动系统和空气之间、小滑轮和转轴之间存在一定摩擦。造成实验结果比真实值偏大的主要因素有两个方面，一是小滑轮的转动惯量和绳的质量不计入实验，二是由于系统摩擦造成系统角加速度没有考虑。只要我们设法测量这两个影响实验结果的因素，把它们计入实验，就能很大程度减小实验误差。我们也可以用振动法测刚体转动惯量。三线摆法属于振动法测质量均匀、形状规则物体定轴转动惯量的一种简单易行方法，缺点是实验简单粗糙，误差较大。它是利用三线摆下盘做角谐振动机械能守恒原理，导出角谐振动盘转动惯量表达式，在加上待测物体时，让盘和物体在三线摆下做角谐振动并测量相关参数值，方可求得待测转动惯量值。 关键词：定轴转动；转动惯量；转动动能；实验误差；误差分析 Some designs and analysis of the experiments to measure the moment of inertia Abstract : Experiment scheme about measuring moment of inertia, the laboratory commonly used dynamic method, using the rotation theorem, based on the rigid body rotation when the measurement of torque and angular acceleration is obtained for measuring moment of inertia. Laboratory core instrument used to measure moment of inertia of rigid body, with small pulley of the moment of inertia instrument, automatic counting device. The moment of inertia instrument the rotational inertia of the rotating system is known. In the experiments, the rotational inertia of the small pulley and rotor winding system and connection weights of cord quality is not considered separately. In addition, the shaft and support between, between rotation system and air, there is friction between small pulley and shaft. Experiment result is larger than real value of the main factors have two aspects, one is the rotational inertia of the small pulleys and ropes are not included in the quality of the experiment, the second is system due to system friction Angle acceleration does not take into account. As long as we try to measure the two factors that influence the experiment result them included in the experiment, can greatly reduce the experiment error. In view of the laboratory commonly used dynamic method, we can also be used to measure moment of inertia of rigid body v