duong kinh pitong nho cua 1 may dung chat long la 2,5 cm. Hoi dien tich toi thieu cua pitong lon la bao nhieu? De tac dung len 1 luc 100 Nlen pitong nho co the nang duoc 1 o to co trong luong 35000 N.
giup minh viet tom tac roi giai giup minh nha! minh dang can gap.