NGHIEN CUU & UNG DUNG
DAY HOC GIAI QUYET VAN DE KIEN T H C C G H U D N G
"CAN BANG VA CHUYEN DONG CUA VAT RAN" (VAT IY ifiP 10) THEO lYTHlYET KIEN TAO
PGS. TS. TtSn Huy Hodng, Nguy6n Song Anh Sun Truimg Bgi hpc Suphgm - Bgi hpc Hui SUMMARY
The education of our country is being carried on lot of teaching renewal at high school, in which the innovation of teaching method according to cultivating thought ability, and solving problem capacity for students is especially cared. Organizing the solving-problem teaching method
which obeys the attitude of constructionism in the process of teaching Physics is highly feasible; it also helps improve activeness of students'learning, forces them to join directly, actively, creatively in cognition process. Since then it will promote extreme thinking ability of learners and improve teaching quality.
Tie khod: Organizing the solving-problem teaching method;
Nlipn bdi ngdy: 20/4/2014. Ngdy duypt ddng: 5/5/2014 1. To chiic day hgc giai quyet van de theo 1^ thuylt kien t^o
Bude 1: Tgo tinh hu6ng lam xudt hifn van d l
Giao vien can nghien ciiu nhung quan niem sin c6 cua HS lign quan din ndi dung kien thirc can xSy dyng, tir dd dua ra mgt hf thong cau hoi, mgt cau chuyen ngdn hoac mgt thf nghifm dan gian dk dua HS vao van dg can giai quyet.
Van dl ngn chgn d day la moi lien hf ma ta can phdt hien hoac giai thfch giita hai dgi lugng hoac hai hifn tugng v$t 1^ v.v. Ket thiic bude mgt HS nhgn biet dugc van d l hgc tgp va cd nhu cau nhgn thiic kiln thiic mdi.
Bude 2: Hanh dgng giai quyet van de Giao vien tgo khong khf hgc tap than thifn, df ng vien khuyin khfeh HS trong qua trinh hgc t§p. Tgo dilu kifn cho HS tham gia vao qua trinh xay dyng kiln thiic va kfch thfch hirng thu hgc tgp ciia HS. Djnh hudng, dgng vign HS neu y kiln (gia thuyet, giai thfch) rigng ciia minh. Sau d6, Giao vien can td chiic cho HS thao lugn.
Djnh hudng HS de dan tdi nhu cdu phai tiln hanh thi nghifm kilm tra sy diing sai ciia cac gia thuyet va hudng dan HS lam thi nghifm, xir ly kit qua thi nghifm. Dong thdi giao vign cdn can
ddi thdi gian cho hgp ly.
Kit thue bude hai, HS rgn luyfn nang lyc nhan thirc, sang tgo, rut ra dugc tinh khoa hgc ve sir vgt hifn tugng.
Bude 3: Dieu chinh quan nifm cii, tiep nhan kien thirc mdi
GV can phan tfch va dua thgm nhChig bdng chimg de hgp thirc hda kiln thiic. To chiic cho HS tranh luan, bo sung va hoan chinh kiln thiic ma HS can thu nhgn. Kit thue bude ba, HS thay cdn phai thay doi quan nifm sai sEn cd, qua dd xay dyng kiln thirc mdi - khoa hgc cho ban than.
Bude 4: Van dyng, ciing co, khdc sau kien thue
Giao vien dua ra nhung cau hoi, bai toan thyc tiln dg HS van dung kien thue mdi, qua do Cling cd, khae sau kien thiic cho HS. Kgt thue bude bdn, kign thiic mdi kien tgo dugc ciia HS se dugc cung cd, khae sau.
2. Van dung qui trinh dgy hgc giai quyet van de theo ly thuyet kien tao trong day hgc chuong "can bdng va chuyen dgng ciia vat rdn" Vat ly 10 THPT
2.1. Dieu tra quan nifm cua HS ve c^c kien thue trong chuong "can bdng vd chuyen dpng cua vgt rdn"
TAP CHi THlfrB(GlA0DgC-S6 1 0 5 - 5 / 2 0 1 4 • 35
NGHIEN CUU & UNG DUNG
Qua vifc tien hanh dieu tra tren 140 HS thudc 4 ldp 10 ciia trudng Cao ddng nghg Dong Nai.
Sau khi digu tra, chiing tdi da tien hanh thdng ke ty If % HS cd cae quan niem khae nhau ve cac kien thiie trong chuang "cdn bdng vd chimin dpng ciia vgt rdn" dg tir dd lya chgn cac kien thiic. Qua dilu tra, chiing tdi nhan thdy HS da cd nhigu quan niem khae nhau ve sy can bdng cua vat ran. Nhung quan niem dd nhin chung la sai (cd 45,3 % HS cho rang chi cd trang thai dimg ygn mdi dugc ggi la trang thai can bdng), hogc chi dung mdt phdn hogc chua day du (35,6 % HS cho rang trgng tam cua vat nao phai ndm trgn vat dd, va nam tgi tam hinh hge cua vdt ran hogc la diem chfnh giiia vgt), chiing ta thdy rdng de thay ddi cac kien thirc ma cac em san cd la khd vi cac kien thiic do da ben r l sau vao trong HS. Vf du, cd den 75,6% HS cho rdng mat chan dg la phan tilp xue vdi mat phang dd cua vgt; 55,6 %HS cho rang mirc vung vang ciia vat phu thugc vao khoi lugng ciia vat; 36,4 % HS cho rang v l can bang ciia mgt vat cd mat chan de la vat cang nang dung cang vting, vat cang cao cang de nga;
45,4% HS cho rang canh tay ddn la khoang each tir true quay den diem dgt cua luc...
Tir ket qua dieu tra quan nifm cua HS trudc khi hgc chuang "can bdng va chuyen ddng ciia vat ran" Vat ly 10 THPT, chiing tdi xac dinh dugc cac don vj kign thiic cd thl triln khai td chiic day hgc giai quyet vdn de (GQVD) theo ly thuyet kien tgo (LTKT) nhu sau:
1- Cach xac dinh trgng tam vat ran, vi cd nhieu HS quan niem khae nhau ve kien thire nay va da so cac quan nifm nay deu sai If eh.
2- Khai niem v l trang thai can bdng, vi ed nhieu HS quan nifm khae nhau kien thiic nay va da sd deu la sai lech.
3- Xac djnh eanh tay ddn cua lyc, vi cd nhieu HS quan niem khae nhau ve kiln thiic nay, da so cac quan niem nay deu la sai Ifch.
4- Xac dinh mat chan de cua vat, vi ed nhieu HS quan nifm khae nhau ve kien thiie nay va da so deu la sai Ifch.
5- Mirc viing vang ciia vat, vi cd nhieu HS quan niem khae nhau ve kign thiic nay va da so
deu la sai Ifch.
2.2. Chuan bf thi nghiem
Dg td churc tot day hgc GQVD theo LTKT, ehung tdi chudn bi m$t so thi nghifm:
Thi nghipm I: Dilu kifn can bdng eiia vSt ran chiu tac dung cua hai lyc
Dung ci^; Mdt bia ciing, hai rdng rgc, hai sgi day, hai lyc ke
Thi nghipm 2: Dilu kifn can bdng ciia v§t ran chiu tac dyng ciia ba lye khdng song song
D^ing c^i: Hai lyc ke, mgt vat phdng m6ng cd trgng lugng P va trgng tam da bilt, mgt day dgi
Thi nghipm 3: Xac dinh trgng tam vat ran phang, mdng.
Dung c\i: Mgt chan de, mgt gia trgng, mft sgi day, nhihig tdm bia phdng co hinh dgng bat ki va hinh dgng dac bift (hinh trdn, hinh vuong, hinh chir nhgt, hinh tam gide, vanh trdn).
i • TAP CHi THIFT BI GlAO Dgc-S6 105 - 5/2014
NGHIEN CUU & UNG DUNG
Thi nghipm 4: Xac dinh digu kien de lye cd tac dyng lam quay vgt
Dimg cu: Vat cd true quay co djnh, cd dye lo dl treo cac sgi day, gia dd tryc quay
Thi nghiem 5: Quy tac hgp lyc hai lyc song song ciing chieu
D{ing cu: Thanh nhe, qua nang, day treo, lyc kl.
Thi nghipm 6:
Diing cii: Mgt khoi go hinh cha nhat, d chfnh gitta mgt mat bgn cd gdn mgt mui ten, miii tSn cd the chuyen dgng quay quanh true, mdt chile ngm.
Dung cii: Mgt thudc thdng dai cd mgt lo d ddu va mgt d chinh gi&a, mgt cai dinh.
Sau khi chudn bi thi nghiem, chiing tdi tien hanh thigt k l tiln trinh day hgc cho 3 bai trong chuang.
Thyc nghifm su pham dugc chiing toi tien hanh tren doi tugng HS ldp lOAl, 10A2, 10A3, 10A4 cLia trudng Cao Ddng Nghl Dong Nai.
Chiing tdi chgn hai ldp TN va hai ldp DC dam bao yeu cau TNSP.
Trong qua trinh TN, chimg tdi tien hanh dgy song song cac ldp TN va ldp DC trong ciing mgt khoang thdi gian, ciing ndi dung chuang "can bdng va chuygn dgng ciia vgt rdn",
Cung trong qua trinh dd, chiing tdi chii y quan sat thai dg, y thirc va kit qua hgc tgp ciia (Xem tiip trang 44)
TAP CHI THlffBIGlAO Dgc-S6 105-5/2014 • 3?
