D
dangdinhhiep
![](https://blog.hocmai.vn/wp-content/uploads/2017/07/hot.gif)
![](https://blog.hocmai.vn/wp-content/uploads/2017/07/hot.gif)
mot vat co khoi luong m=20kg dang dung yen thi dc keo truot tren be mat nam ngang boi 1 luc ko doi f=50 n,he so ma sat giua vat va mat duong la k=0.2 bieu dien luc va cho biet cac luc co hoc do thuoc loai luc nao va tinh gia toc van toc q®uongi dc sau 3s![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
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chú ý gõ dấu
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chú ý gõ dấu
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