cgl{c HoA xA uqll cnu xcnia lr4r UBND T1NH THAI NGUYSN SO GIAO DUC & OAO TA.O DQc cHeN Hgc slliH cror cAr Mdn: Vit li - Nlm h9c.2015 - 2076 Thdi gian: Bii l0p - Trl - Henh Phtic ri, uu of csixs rrrUc 180 NAM philt (kh6ng ke thdi gian giao rixu LoP t2 d€) MQt dAy cao su nhe dan h6i co chieu dd,j AB : /0 : 1ffi, cci luc ddn h6i tuAn theo dinh iuAt lltic Mgt dAu so-i diy duo-c treo o A, dAr,r gin vAt co lchtii lugng M : 0,2 kg DAy din tioan OB vd v6t nim o vi tri cAn bing O K6o vflt xuong doan OC = 0,10 m r6i bu6ng nhq (ilinh 1) V4t dao d6ng di6u hod theo phuo'ng thdng dirng vo'i chr.r ki T: 1s Ldy g =' 10ir/s2 I16y tinh: ,( , , ) a) HQ so ddn hoi cr"ra dAy b) Vdn toc cira vAt o'vi tri D, v6i OD : I -lhoi gian c) de vdt di ru C clcn D 2.YXm duoc nAng 10n c16n vi tri A roi duo'c thi roi tu Tim tho'i gian 116 vAt M quay lai vi tri A 1An thu nhdt ke tu vit duo'c th6 I]iri Cho mach di6n nhu hinh C i : 0,05 m t; Hinh L,r Tudi6nc6di6ndungC,cu6ndAyc6r16trrcami-vidi€ntrrr.- ]M , : \ \4 thuan r.,i dj€n trcv thuin R co gid rri thay doi duoc \4ac hai darr A A : Hinh B vio ngu6n di6n xoay chi€r,r c6 hi6r"r di6n th€ nrc tho'i lJo" 1,-o ) .-: i ^ ^ cos2rft(v) Tin so lcira ngu6n