项目背景
项目目标
项目设计
预期成果
学习资料
认识超声波传感器
https://baijiahao.baidu.com/s?id=1628988342194027424&wfr=spider&for=pc
https://wenku.baidu.com/view/e61505fbaef8941ea76e0510.html?sxts=1584408586409
杠杆原理
https://haokan.baidu.com/v?vid=7817002455054756126&pd=bjh&fr=bjhauthor&type=video
https://haokan.baidu.com/v?vid=8085470312668316726&pd=bjh&fr=bjhauthor&type=video
电磁感应现象
https://haokan.baidu.com/v?vid=12321273666695216377&pd=bjh&fr=bjhauthor&type=video
https://haokan.baidu.com/v?vid=7776006820197964512&pd=bjh&fr=bjhauthor&type=video
