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daicadn


mot vat khoi luong m dao dong dieu hoa tan so 0.5Hz.Vat wa VTCB voi toc do Vo=31.4cm/s khi t=0 qua vi tri co li do x=+5 cm nguoc chieu duong quy dao .r^2=0.Goc toa do tai vi tri can bang .PT dao dong dieu hoa cua vat ???..