NGHIEN c u f u & UfNG DUNG
Sl/ DUNG CHAI NHl/A, VO LON CHE TAO
THIET BI DAY HOC V A T LI
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• P G S . T S N g u y i n N g o c HUng Tradng DHSP Ha Noi
LTS: TiTlam TBDH diTtfc nganh GD-DT quan tam; vuTa qua, Bp fla thong qua fle an ue tiTlam TBDH. Vafn fle nay cung fla fltfflc giao vien, hpc sinh quan tam hirdng iihg. Trong flo, co fle tai tiTiam TBDH tir cac vat lieu flfln gian re tien cua PGS.TS Nguvin Ngpc Hnhg. De tai fla fliAfc nhom cac tac gia Nguyin Thanh Chung, Tran Van Nam, Nguyen Van Bien va Tran Ngpc Chat thiif nghiem trong nhieu nam. GS.TSKH.J.-H.Wilke (triTflng Dai hoc Tiing htfp kf thuat Dresden - CHLB Dufcl fla neu y tirdng, xay diAig va flong gop nhieu y kien ve cac thi nghiem. De tai fla fliAf c fliTa vao cac Iflp hiii dirilng giao vien vat li trung hoc cd si). Tap chi TBGD gidi thieu mpt siTthi nghiem ma han flpc quan tam
1. NhiTng Uu d i e m cCia cac d g n g cg thf n g h i # m dU^c lam t u chai nhga va v 6 Ion
a) Cac tint) chSt Uu viet cua ciiai nhga vi vd Ion: Chai nhya va vo Ion la hai vat lieu de kiem, rd tien. Chung c6 nhOng tinh chat Uu viet sau:
- Ben, ddo, de gla cong (dye l5, c i t tach thanh chai nhya hoSc thanh v6 Ion...), de sir dyng b i n g tay. Nhd vay, mot so thf nghiem vat II CO the tien hanh dupe vdi dyng cy dupc lam tU chai nhya va vo Ion, ma khdng the tien hanh vdi dyng ey b i n g thijy tinh.
- Cd day vOng e h i e : day ed gd tron, dciy va dupe lam lorn vao trong (dd'i vdi v6 Ion), day dupc g i n them mpt Idp de nhya (do'i vdi ehai nhya).
- Dd'i vdi ehai nhya: each nhiet va each dien td't, trong suo't nen quan sat ro mpl bd' trf va hien tupng vat If x i y ra ben trong nd. Con doi vdi v6 Ion: dan nhiet, chiu nhiet td't va dan dien td't.
Cac tinh chat nay r i t thieh hpp do'i vdi viec ehe tao cac dyng ey thi nghiem ddn gian va doi vdi viec tien hanh nhieu thf nghiem vSt li, dSc biet la cac thi nghi§m vdi c h i t l6ng vk c h i t khi.
b) NhUng Uu diem cCia cic dung CO thi nghiem dugc lim til chai nhUa vi vd Ion:
- Ngoai hai vat lieu chfnh la ehai nhya va v6 Ion, cac dung ey thi nghiem dupe trinh bay doi h6l it bp phan phy trp. Cac bp phan nay de kiem hoSc de che tao tC/ viec gla edng eae vat lieu ddn g i i n b i n g cae edng cy thong dyng nhu kim, bua, kim, keo, cua s l t , dao, giua.
- Cac bp phan cua dyng cy thi nghiem de l i p rap va thao rdi.
V) vay, 6 mpt so' thi nghiem, ta chf can thay the bp phan phy trp la cd the lam dUpc thi nghiem khac, khdng nhat thie't p h l l thay ehai nhya hoac vo Ion khac.
- VI dyng cy thf nghiem khdng cd bp phan b i n g thijy tinh nen de bao quan va van chuyen, an toan trong qua trinh thi nghiem.
- Viee bo tri va tien hanh thf nghiem vdi nhufng dyng cy nay deu ddn gian, khdng td'n nhi6u thdi gian. Hien tupng vat If dien ra trong thi nghiem ro rang, d l quan sat.
2. Hi$u qui day hpc cua v i ^ c sii d g n g cac d g n g eg thf n g h i e m dU0c lam tC/chai nhi/a va v 6 Ion
Viec sil dgng cac dyng cy thf nghiem dupe lam tU ehai nhya va v6 Ion gdp phan nang cao hieu q u i day hpe vat li 6 trUdng pho thdng, cy the la:
- Cac d y n g ey thf nghiem nay giup hpc sinh (HS) de dang nhan thUc ban chat vat If cua nhOng hien tUpng dien ra trong cac thi nghiem dUpc tie'n hanh vdi chung.
- Viec tie'n hanh thi nghiem va g i l l thich ke't qua cua mpt so' thf nghiem ddi hdi HS phai huy ddng cae kien thUe da hpc 6 nhieu phan khac nhau cua vat If. Thdng qua d d , cac kien thUc ma HS da ITnh hpi dupe eung eo, dao sau va he thd'ng hda. Viec sCf dyng mpt so' thi nghiem n h i m minh hpa lai nhufng thi nghiem do chinh cac nha bac hpc da lam se gdp p h i n boi dudng cho HS cae phupng phap nhan thUc vat li, dSc biet la phUPng phap thyc nghiem. Vf dy: Khi de cap sy truyen ap s u i t trong c h i t long va ehat khi 6 Idp 8, HS cd the dupc giao nhiem vy che tao dyng ey thi nghiem va tien hanh thi nghiem ve nguyen t i e cau tao va boat dpng cija dyng
^..^l^^Z^.i^^.im^^...S:W^Um^.^^^. 86 57 thang 5 nam 20101 3
NGHIEN cufu & UfNG DUNG
ey dieu khien rupu c h i y ra ciJa He - r d n (hinh 1)
Hinh 1
Nhiem vy che tao nhiJfng dyng cy thi nghiem nay va sir dyng chung de tie'n hanh cac thi nghiem vat li lam t&ng hUng thu hpe tap vat li, phat huy tinh tfch eye, phat trien nSng lye boat dpng tri tue - thyc t i i n dpe lap va sang tao cua HS.
3. Cac k h i nang sil dgng trong day h^c vat If nhOng thf nghiem dU^c tien hanh vdi dgng cg dU^c lam tii chai nhi/a va v6 Ion
1) Cic thi nghiem co the dugc si!l dung d tii ci cic khiu cua qui trtnh d^y hqc
Nhu'ng thi nghiem dUpc tie'n hanh vdi dyng ey dupe lam tCr chai nhya va vo Ion cd the dupe sii dyng de d&t van de (tao tinh hudng cd van de), hinh thanh kien thufc mdi (kiem tra cac g i i thuyet da neu, kiem nghiem kien thUc da dUpc rut ra b i n g suy luan li thuye't tCr cac kien thufc da biet), cung ed' va van dyng cae kien thUc da hoc (trong dd cd viec de cap cac ijfng dyng eua kien thufc vat li trong s i n xuat va ddi so'ng) va cung cd the dung de kiem tra, danh gia kien thUc, kTnang cua HS.
Cac v i d y :
- Khi day "ap suat khf quyen"
d Idp 8, giao vien (GV) cd the sil dyng thi nghiem hieu Ung cua ap suat khi quyen de tao tinh
hudng cd van 66. Thi nghiem nay cung cd the dupc sif dyng 6 khSu cung co cac kien thitc ve ap s u i t khf quyen ma HS da dupe hpc. HS p h l l van dyng dupc eac kien thufc nay d l ti§n doan hien tupng x i y ra trUdc khi tie'n hanh thf nghl§m
Hinh 2
2) Cic thi nghiem co the dugc SLI dung trong d$y hoc vit It dudi nhieu hinh thUc khic nhau
• Viec che tao va si!r dyng cac dyng cy d l tien hanh cae thf nghiem ed the giao cho tUng HS hoSc cae nhdm HS lam 6 nha hay trong gid ngoai khda, khdng nhOfng de eung ed' cae kien thiifc da hpe ma co khi edn d l cung cap cac cU lieu thyc nghiem chuan bj cho ndi dung kien thufc 6 cac bai hpc sau.
Vf dy: Cac thf nghiem ve sy c h u y i n hda giOfa cac dang nSng lupng khdng nhOng cd t h i dUpc sil dyng mpt phan khi de cap djnh luat b i o toan va chuyen hda nang lUpng 6 Idp 9 (hinh 3) ma edn tao dieu kien thuan lpi d l xay dyng npi dung hpe tap
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Hinh 3
ngoai khda ve d l tai n^y - mdt de tai ed r i t nhieu ufng dyng trong ddi song va kT huat.
- GV cung cd the lam thf nghiem tren Idp vdi dyng cy thi nghiem dupe l^m tU ehai nhya va v6 Ion, yeu c l u HS v l nha che tao lai hoac che tao dyng ey thi nghiem theo phUdng an khac (neu cd). V i dy: D l k h i o sat s y phy thupc cua kha nang ha'p thy bUc xa nhiet cua vat vao tfnh c h i t be mat cija n6 (Idp 8), GV bleu dien tren Idp thi nghiem vdi hai v6 Ion dUpc sdn den va sPn t r i n g , chufa cung mpt lupng nudc. Cac v6 Ion nay dupe ehie'u sang nhd den hong ngoai hay den day tdc ed eong s u i t Idn. Sau dd, GV giao eho HS nhiem vy ehe tao dyng eg va tien hanh thf nghiem nhUng vdi v6 Ion dupe phu muoi den va v6 Ion dupe cao b6 Idp sdn phu ngoai. Thay cho viec dung den chieu sang, HS phdi dyng cu thi nghiem dUdi anh ning mat trdi. GV yeu cau HS so sanh hai phUdng an che tao d y n g cy va tie'n hanh thf nghiem da neu tren.
Vdi dyng cy thf nghiem ddn gian tif ehai nhya va vo Ion do minh che tao, HS tien hanh lai thi nghiem ma GV da bleu dien tren Idp nhung nghien cufu sau hon cac md'i lien he giijfa cae dai lupng vat li dupe de cap trong npi dung thf nghiem hoac tien hanh cac thi nghiem chua dUpc lam tren Idp.
Dil dupc tien hanh dUdi hinh thUe nao thi viee thiet ke, che tao cae dyng ey va tien hanh cac thi nghiem c i n dupe giao eho HS dudi dang nhOng nhiem vy nhan thiJc ed ndi dung sao eho phat trien nang lye boat dpng tri tue - thyc tien cua HS, ehU khdng dPn thuan ehl la hoat dpng tay chan don gian.B
So 57 thang 5 nam 2010
