cgl{c HoA xA uqll cnu xcnia lr4r<br />
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UBND T1NH THAI NGUYSN<br />
SO GIAO DUC & OAO TA.O<br />
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DQc<br />
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cHeN Hgc slliH cror cAr<br />
Mdn: Vit li - Nlm h9c.2015 - 2076<br />
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Thdi gian:<br />
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l0p - Trl do - Henh Phtic<br />
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ri, uu<br />
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of csixs rrrUc<br />
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MQt dAy cao su nhe dan h6i co chieu dd,j AB : /0 : 1ffi, cci luc ddn h6i tuAn<br />
theo dinh iuAt lltic. Mgt dAu so-i diy duo-c treo o A, dAr,r kia gin vAt co lchtii<br />
lugng M : 0,2 kg. DAy din tioan OB vd v6t nim o vi tri cAn bing O. K6o vflt<br />
xuong doan OC = 0,10 m r6i bu6ng nhq (ilinh 1). V4t dao d6ng di6u hod theo<br />
phuo'ng thdng dirng vo'i chr.r ki T: 1s. Ldy g =' 10ir/s2.<br />
1. I16y tinh:<br />
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a) HQ so ddn hoi<br />
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cr"ra dAy.<br />
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b) Vdn toc cira vAt o'vi tri D,<br />
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de vdt di ru C clcn D.<br />
2.YXm duoc nAng 10n c16n vi tri A roi duo'c thi roi tu do. Tim tho'i gian 116 vAt<br />
M quay lai vi tri A 1An thu nhdt ke tu khi vit duo'c th6.<br />
I]iri 2<br />
Cho mach di6n nhu hinh 2.<br />
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B vio ngu6n di6n xoay chi€r,r c6 hi6r"r di6n th€ nrc tho'i lJo" 1,-o<br />
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