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人民教育出版社普通高中课程标准实验教科书《物理》选修3-4中,第12章第7节《多普勒效应》一节提到了多普勒测速仪.交通警向行进中的车辆发射频率已知的超声波,同时测量反射波的频率,根据反射波频率变化的多少就能知道车辆的速度.〔1〕但是多普勒测速仪的工作原理是怎样的?它是怎样测量车速的?教材中未作说明,这里试图作出推导研究.大家知道,由于波源或观察者的运动而出现了观测频率与波源频率不同的现象,这是奥地利物理学家多普勒在
People’s Education Press ordinary high school curriculum standard experimental textbook “Physics” Elective 3-4, Chapter 12, Section 7 “Doppler effect” section referred to the Doppler velocimeter traffic police moving vehicles firing frequency Known ultrasound, while measuring the frequency of the reflected wave, can know the speed of the vehicle based on how much the reflected wave frequency changes.1 But how does the Doppler velocimeter work and how does it measure the speed? Is not illustrated here trying to deduce the study.As we all know, due to the movement of the wave source or observer and observed frequency and wave source frequency phenomenon, which is the Austrian physicist Doppler in