H
hocdethithilado


chao thay (co)! em thay cai de kiem tra ly luyen thi DH dam bao cua thay thao. bai nhung cau hoi thuong gap trong DĐĐH bi loi~ 1 so cau vd nhu cau so 5 luc phuc hoi td len vat khi qua vi tri thap nhat = l1-4l.200=6N moi dung chu a. con cau so 4 tinh ra goc fi= -pi/2 thi ptvt phai la v=-wAsin(wt-pi/2) chu' sao lai la v= wAsin(wt-pi/2)