JOURNAL OF SCIENCE OF HNUE Educational Sci , 2009, VCJI 54, No 8, pp 23 27 CHE TAO THIET BI THI N G H I E M T 6 N G H O P HAI DAO D Q N G DIEU HOA D U N G TRONG D A Y HOC VAT LI 12 d T R U C J N G T H[.]
JOURNAL OF SCIENCE OF HNUE Educational Sci., 2009, VCJI 54, No 8, pp 23-27 C H E TAO T H I E T BI T H I N G H I E M T N G HOP DAY HAI DAO D Q N G DIEU HOA D U N G TRONG HOC VAT LI 12 d T R U C J N G THPT Dudng Xuan Quy Trudng Dai hoc Su pham Hd Ndi M d dau Trong chudng trinh Vat If 12 d trirdng THPT, kiin thQe vi tdng hdp hai dao dpng diiu hda la npi dung quan trpng ma hpc sinh (HS) cin chiim linh Di thue hien tdt nhat qua trinh nay, viec td chQc hoat dpng hpc cho HS cin di theo tiin trinh sau: ThQ nhit, hudng din di HS giai quyit bai toan If thuyit [1, 2, 5]: Mot vdt thuc hien ddng thdi hai dao ddng diiu hda ciing pliuang, cung tdn sd, cd phuang trinh chuyen ddng la Xi = Ai cos{u}t + ^\) ua X2 = A2Cos{u}t -|- (^2)- Tim phuang trinh dao ddng tdng hap? Vdi cac kiin thQe da dupe trang bi (phuPng phap biin ddi lupng gidc hoac phuong phdp vec td quay Frex-nen), HS se tim dupe phupng trinh chuygn dpng tdng hdp co dang: x = Acos{ujt -+- gj), dd bign dp A va goc pha ban diu (/? dupc xac dinh theo cae cdng thQe: A-y r A , , N AlSin^Pl + A2sing:)2 A