多普勒效应表述中的一个常见错误

A Common Error in the Expression of Doppler Effect

关于波源和接收器相对于介质都在运动时的多普勒效应公式中正、负号的选择,目前部分教材和文献中的表述是错误的,其错误在于忽视了波源和接收器相互靠近或相互远离时分别有三种情形,而不是分别只有一种情形.本文分析了这一错误,所得结论对教师讲授和学生学习相关内容有较大的参考价值.

Representation to choose Positive and negative signs of Doppler effect formula,which is about both the wave source and receiver having relative motion to the medium,is wrong in some books and literatures at present.The cause of the error is that it neglects the fact that there are 3 cases rather than 1 case exists,when the wave source and the receiver are drawing near or going far mutually respectively.The error is analyzed,and the conclusions have important reference values for teachers＇ lectures and students＇ learning related contents.