CHt TAD VA SlJl DUNG CAC THI N G H p VE SD TIT HDA CDA CAC CHAT VAO DAY HOC MON VAT LJ U TRUNG HOC PHO THONG ThS HA DUYEN TUNG '''' Khi hpe SutUhoacua cacchitihuoc chuong r / f f r v o n j (Vat li 11} tr[.]
Trang 1CHt TAD VA SlJl DUNG CAC THI N G H p VE SD TIT HDA CDA CAC CHAT VAO DAY HOC MON VAT LJ U TRUNG HOC PHO THONG
ThS H A DUYEN T U N G '
r / f f r v o n j (Vat li 11} trung hpc phd'thdng,
hpc smh (HS) can n l m dupc su tif hoa cua
eac ehat thuan tu, nghich ti^vi sittO-khi dat ehung
trong td tn/dng ngoai Hien nay, khi hpc tap eac kien
tilde nay, HS phai "hpe chay" vi chua ed cac thinghiem
(TN) de giao vien (GV) to ehu'c cac hoat dpng nhan
Blue cho HS.Trong tti ucle,HS da biet khisit, til ep dat
trong lOr trudng cua nam cham thi bj nam cham hut
nhung khi dgt dong, nhdm trong tir tnrdng cua nam
cham thi dong, nhdm khong chju lueliirtac dung Quan
ni?m dong, nhom dat trong tu'trudng cua nam cham
khdng chiu luc tutae dyng la mot quan niem sai lam
cua HS Dong la ehat nghich tCrnen khi dat dong trong
tCriR/dng cua nam cham se chiu luc day, cdn nhom la
chat thuan tiise chju lue hut Tuy nhien, eac luc tuong
tac nay rat nho nen khong dedang quan sat thay dupc
Vi vay, viee chetao cac TNvesutuhoa cua eae ehat de
su'dung trong day hpc (DH) eac kien thdc nay nham
phat huy linh tich cue, nang Iyc sang tao eua HS va
khic phyc sai lam cua HS la mot yeu cau cap thiet
I C h e t a o T N m d h i n h mien t u hoa t u n h i e n
cuachHtsatttf
1) Che tao TN
md hinh mien tu
hoi ttr nhien cua
chai sat tlf Gh\m
giaiy (1) dupc g i n
vaomiJd6ng(2)va
dupc dgt can b i n g
tren mpt dinh (3)
Cac dinh (3) dupc
elm thing dung
trSn mdl tam nhua,
mdi dinh each
nhau 4 cm Hethong eac ghim giay (1), mu dong (2)
va dinh (3) dupe d§l Irong mpt hop nhua (4) co mat
tren la mica sao cho khi di ehuyen cac ghim giay
khong bi roi ra khoi mu dong vadinh
Hinh I TN mo hinh miin lir hod
lu-nhien cua chai sdi lu
Moi mpt ghim giay dupc coi nhumpt mien tOrhoa tunhien cua chat s i t tir
2) Cic TN duqv tien hinh vdi TNmo hinh mien
tu hoa tu nhien cua chatsittiyx\[\
khong cd tir Irudng ngoai, cac ghim giay dupc s i p xep hon ddn, khdng theo trat tu Sat he thong eac ghim giay
d Iren trong i\i
tardng ngoai cua nam cham vTnh cuu thi cacghim giay dat
s i p xep lai theo hudng cua tirtn/dng ngoai
2 Che tao TN Chung minh t i i tinh cua s i t b j m a t khi qua nhiet dp Quy-ri
1) Chetao TN ehung minh ti/ tinh cua sit bj
mii ichi qui nhiet do Ouy-dDoan s i l non (1) dupe
UOTi thanh moc trdn detreo vao giadd(2)vacdthedao dpng tren giadd (2) Nam cham vTnh cuu (3) dupc dat Iron phuong dao dpng cua doan s i t non sao cho khi doan s i t non bi hut ve phia nam cham nhung khdng tiep xucvdf nam cham Cay nen (4) dupc dat phia dudi doan s i t non khi bi nam cham hut
Hethong doan s i t non, giadd, nam eham vacay
nen dupc bo tri nhu hinh 3
2) Cic TN duac tien hinh vai TN ehung minh tutinhcuasitbjmiikhiquinhietdqQuy-ri.Qua
doan sat non (1) lai gan phia nam cham vTnh cutj (3),
Hinh 2 TN ehung minh lir Ilnh ciia sdt bl mdl khi qua nhiet dg Quy-ri
(ki2-4/2013)-' TrVdne THPT Dan IQC noi tni tinh Thanh Hoa
Tap chi Gide dye so 308 | 55
Trang 2mat khi qua nhiet dp Quy-ri va TN ehung minh tinh
ehat tiiuan tu, nghich tu, ehung toi tien hanh sopn
thao tien trinh DH cac kien thtrc ve s u ti> hoa eua cac chat theo sffrfd'sau:
Hinh 3 TN ehung minh linh chdl ihugn lir nghjeh ta
sau khi chiu luc hiit cua nam eham, ttianh s i t n l m
can b i n g Dat cay nen (4) phia dudi doan sat non
Quan sat TN sau khicham lua decay nen chay va
nJt ra ket luan: khi doan s i t dupc nung ndng den nhiet
dp nhat djnh nam cham khong hut s i t nira vi chuyen
dpng nhiel cua eac nguyen tii'sedu manh de lam tan
ra hoan loan cac mien tCr hoa l u nhien, cac tinh chat
s i t t u s e b i mail di
S C h e t a o T N Chung m i n h tinh chait thuan t l i ,
nghjeh t u
1) Chetao TN chiing minh tinh chait thuin hi,
nghjeh hi:-Mqi doan donq (1) cd dudng kinh 3mm,
chieu dai Scm dupc e l m thang durig tren mdt mieng
xop (2) nho Mieng xop iuqc dat tren mat nude cua
mpt khay nudc (3) cd kich tti udc 30cm X 20cm x 6 e m ;
- Mpt nam cham vTnh cuu (4) co kich tiiudc 6em x
3cm X 1em; - Doan nhom (5) cd kich thude b i n g
doan dong va cung duoc d m tiling diitig tren mieng
x6p(2)
2} Cac TN tie'n hinh vdi TN chiing minh tinh
chiithuin tii, nghich tu Muc dieh cua T N : ehung
minh dong cd tinh chait nghjeh ti> va nhdm cd tinh
chaitthuantd,
Lan lupt e l m ttiing dung cac doan dong va nhdm
len tren mieng xop nho Oat mieng xop tren mat nudc
cua khay nudc, sau dd dua nam cham vTnh cuxi lai
gan doan dong v a n h d m Ket qua T N : nam eham day
doan dong va hiit doan nhdm Ket luan: khi dong dat
trong 10* trudng cua nam cham vTnh ci/u thi bj nam
cham day nen dong ta chat nghjeh tu^ nhom dat trong
tu'lR/dng cua nam cham vTnh cuu thi bj nam cham
vinh cuu hut nen nhdm la chat thuan tir
4 S u d u n g c a c T N da c h e t a o t r o n g DH c h u o n g
Tiitudngmon Vat ( i l l
Sau khi da chetao cac T N m d h i n h mien tiThoah/
nhien cua chat s i t tiir, TN ehung minh tilrtinh eua s i t bi
1 Lim niy sinh w£n d( d n glal quy<l Tu kiSn inOc cO DJI Ihanh sil troog lu IruOng cua nam efiSm lhi quon sdi thiy inanh sAl hi hiil vfl phia
2 PMt biiu vCn dt cdn glal quy<t: TharW siliM cSu Injc nhu (hfi niovi phuwig dren lu Wli mi ffianh 5^1 041 trong lit xnjijnq ciia nam chim (hi hi hLrt vi phia nam eftflni^
*^
3 Giat quy<( vtn d l 3.1 BtMutigamu^:
rtitu lum nam cItAm nho
V6 phirong di«n tlK Ihanh sil e6 cSu true gfim rSt Aim sip xfip h6n ain
CO tu linh - Ktv Oil trong Itf inMng ngoii cua
cua tLI trudng ngoai cic jm nam chim nho
XnlOng ngoii Khi M thanh sAl c6 tu tinh v i 1
tnWnonooii-m 4 l
eO»
hut
Khi Ho Ihanh sit kliAi^ iam chim Afi)! tic dvng
u h i n ^ sip xfip theo til
vi phia nam chim tgo tu
3J KHim tn linh dOng din eii* gia thuyit': - Suy lujn logic tit gia fliuyfil
ra hfi qui kifim tra tlupc in/c lifip nhdt TN: Nung ihaiVi sit ax\g iJuijc d^t
nhifit cua cfic nguyfin ti} sit du mgnh dfi lim tan rfi mifin iCi hofi ti; nhifin ti)
tinh cua Ihanh s^ b\ mSl Ihanh sit khfing b) nam chim hiit: - Thifit Ml
tinh cua chit sit lu b| mfit khi qui nhifit dfi Ouy-rl: • Thi/c hifin TN cho kfil qua nung nfing Ihanh sit dfin mfit nhifil dfi nhfil djnh Ihl thanh sit khfing bl
A Rut ra kfil luf n TN khfing dinh tinh dUng din cua hfi qua gia thuyfit ttfi
Ihanh kifin Ihuc ITKII - Vfi phuiTng difin ICr ihanh sil c6 efiu true gfim ifil
nhifiu 1(im nam chim nho' du^c sip ifip hfin dfin, Khi M thanh sit khfing
cfi lit Ilnh Cic "kim nam chfim nhfi' niy dugc gpi l i cic mtfin tif hoi 11/ nhifin Mfil mifin dfi cfi kich thuiic cO 0 01 • 0.1 mm v i chiJa khoing 10" -10" nguyfin tij- - Khi dit trong tu trudng rigoii cua mfit nam chim duOi tic
dung cua tit Irufing ngoii cic kim nam chim nhd cfi xu tniOng sip ifip
theo lir Irudng ngoii - NIu nhifil dfi ciJa manh sSl Ifin hon mfil nhifit dfi T^
nio dd Ihl dfic nnh sit tu cua nfi khdng cdn nOa Nhifit dfi T^ goi l i nhifit dfi
f U m nay afn/i vJii dtf C^n fftf/9104) Mp: Kfil hifin Ufin d u n nil ra til
TN vdl manh sil dfit uong til tnrdng ngoii cua nam chim vinh cuu Cfi Difi thay thanh s i l bhig cic thanh afinp nhflm
!' Phil biiu rgh Ot ctn glil quyfi: Khi dfii thanh dfing v i nhflm trong ti/
khOng''Nfiu cfi thi kre tic dung ciia lif tn/dng ngoii c6 dfic difim gl?
' Gial quyel vtn dt:
'.f D6 niSt gm Ihuygi Km dfilthanh ifdng v i nhfim trong tir irufitig ngoii
li Ihanh dfing v i rtfiflm chju lie di;nH cui lif trudng ngoii mfil liff rfit nhp
3S Kiim ba tinh Oung ain eua gii Ihvyit • Thifii kfi phuong i n TN oS
lu, - Thuc hifin TN cho kfil qui thanh dfing v i nhfim dfii trong lu trudng
lAwng ngoii Ifln Ihanh dftng lfi lgc diy Ifin Ihanh nhfim l i luc hut
4: ROt ra M} fufiv - Khi dfing v i nhflm dfll irong tir inrdng ngoii sfi di|u
tic dung cua lir truong ngoii mfit k;c rit r M Dfing v i nhdm cOng b| tir hod
kh dfii trong tir irudng ngoii nhung Unh \il hoi yfiu - Cic chil ed Ilnh lu
hoi nhu dfing v i nhfim go> l i Chit chil thuin tir v i nghich ICr (dfing l i chSt nphch tu nhflm la iJiS ttiujn tul
Cae thi nghiem tren da tao dieu kien eho GV
(Xem dep trang 54}
56 Tap chi Giao due so 308
-(kt 2-4/2013)