初中物理知识点总结
以下是小编为大家准备的初中物理知识点总结,本文共19篇,仅供参考,欢迎大家阅读。 初中物理知识点总结 1. 物体在振动,我们“不一定”能听得到声音 【简析】 1、声音的传播需要介质,在真空中声音是不能传播的,登上月球的宇航员们即使相距很近也要靠无线电话交谈。 2、人的听觉是有一定的频率范围的,即:20~0Hz,频率低于20Hz的声波叫次声波,如发生海啸、地震时产生的声波是次声波;而频率高于2000
wp-content-crawler
domain was triggered too early. This is usually an indicator for some code in the plugin or theme running too early. Translations should be loaded at the init
action or later. Please see Debugging in WordPress for more information. (This message was added in version 6.7.0.) in /www/wwwroot/cuomi.com/wp-includes/functions.php on line 6121