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共振现象是自然界中极为普遍的现象.在机械振动中,当策动力的频率与系统的固有频率一致时,受迫振动的振幅达到极大值.这种现象称之为共振.做好共振演示实验特别重要,笔者根据教学实际总结了一些演示方法,实验的可见度不同,供同行们参考.一、应声法沈括在《梦溪笔谈》中精心设计了一个声学共振实验.他剪了一个纸人,把它固定在一根弦上,弹动和该弦频率成简单整数比的弦时,它就振动使纸人跳跃,而弹其他弦时,纸人则不动.沈括把这种现象叫做“应声”.用这种方法演示共振是沈括的首创.在西方,直到15世纪,意大利人才开始做共振实验.至今,在某些国家和地区的中学物理课堂上,教师还使用这种方法给学生做关于共振现象的演示实验,十分形象生动,能激发学生学习物理的强烈兴趣.
The phenomenon of resonance is an extremely common phenomenon in nature. In mechanical vibrations, the amplitude of the forced vibration reaches a maximum when the frequency of the power is consistent with the natural frequency of the system. This phenomenon is called resonance. Experiments are particularly important. The author summarizes some demonstration methods based on teaching practice. The visibility of the experiments is different and can be used as a reference for peers. First, Shen Kuo, an acoustic method, carefully designed an acoustic resonance experiment in Mengxi Bi Tan. He cut a paper man. When it is fixed to a string, and it flicks a string with a simple integer ratio to the string frequency, it vibrates to cause the paper person to jump. When the other string is played, the paper person does not move. Shen Kuang called this phenomenon “Response”. Demonstrating resonance in this way is the first of Shen Kuo. In the west, until the 15th century, Italian talents began to do resonance experiments. So far, in some countries and regions in the middle school physics class, teachers also use this kind of The method gives students a demonstration experiment on the resonance phenomenon, which is vivid and vivid and can stimulate students’ strong interest in learning physics.