DE THI TUYEN SINH DAI HQC, CAO DANG NAM 2008 MonthI: V A T L I - K h o i A Thdi gian lam bai: 90 phut Cdu 1: K h i chieu I a n liftft h a i buTc xa c6 t a n so l a f^, iz ( v d i fi < £ ) vko mot qua cau k i m loai dSt c6 lap t h i deu xay r a h i | n ttfcfng quang d i e n v d i dien the cifc d a i cua qua cau I a n lufdt la V i , V2 Neu chieu dong t h d i hai bufc xa t r e n v^o qua cau t h i d i e n the cifc d a i cua no \k: A V2 B (Vi + V2) C Vi D, IVi - V2I Giai Vi fi < f2 n e n V2 > Vi Neu chieu dong t h d i h a i bufc xa t r e n v^o qua cau t h i d i $ n the cifc dai cua no chi hang d i e n the I d n hcfn, c h i n h la V2 Vdy chon dap an A Cdu 2: T r o n g t h i n g h i e m ve song dCrn^, t r e n m o t stfi day d a n h i d^i 1,2 m v d i h a i dau co d i n h , ngUdi t a quan sat t h a y ngoai h a i dau day co d i n h co h a i d i e m khac t r e n day k h o n g dao dong B i e t k h o a n g t h d i gian giOfa h a i I a n l i e n tiep sgti day duoi t h i n g l a 0,05 s V a n toe t r u y e n song t r e n day l a : A 16 m/s B m/s C 12 m/s D g m/s Giai Theo de b a i t h i t r e n day tao t h a n h m u i song, m o i m i i i s6ng co chieu dai — T a c o : - = 1,2 = > = 0,8m Khoang t h d i gian giffa h a i I a n l i e n t i e p stfi day a j j t h i n g l a 0,05s nen t a co chu k i T = 0,05.2 = 0,1s V a n toe t r u y e n song t r e n day: ^ 5i, = ^ ~ "QT ~ ^C™'^)' Vdy chon dap an D Cdu 3: Doi v d i SLT Ian t r u y e n song dien tCf t h i A vector ciTdng dien triJdng E va vectcf cam ufng tCr B luon vuong goc v d i phtTcfng t r u y e n song Giai Chi tiSt (3e thi TS DH, CO M6n vat li