Cov lus nug piv txwv txog kev ntsuas

12 Piv Txwv ntawm Cov Lus Nug Txog Kev Ntsuas

1. Cov txiaj ntsig ntawm kev ntsuas txoj kab uas hla ntawm pob zeb siv lub ntsuas qhov ntsia hlau, qhia nyob rau hauv daim duab hauv qab no, txiav txim siab qhov loj ntawm lub cheeb ntawm lub marble!
A. 4,78 hliPiv txwv kev ntsuas lo lus nug 1
B. 5,28 hli
C. 5,70 hli
D. 8,50 hli
E. 9,28 hli
Kev Sib Tham
Lub micrometer ntsia hlau siv cov chav millimeter thiab nws qhov ntsuas me tshaj plaws yog 0,01 millimeters.
Qhov ntsuas tseem ceeb = 4,5 millimeters
Qhov ntsuas tig = 27,5 x 0,01 millimeters = 0,275 millimeters
Qhov ntsuas tau = 4,5 millimeters + 0,275 millimeters = 4,775 millimeters = 4,78 millimeters
Cov lus teb yog lawm yog A.

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Piv txwv ntawm cov lus nug txog lub zog hluav taws xob

6 Piv txwv ntawm cov lus nug txog lub zog hluav taws xob

1. Ib tug tub ntxhais kawm ntawv qhib TV li ntawm 6 teev txhua hnub. Lub TV txuas nrog lub hwj chim 220 Volt, yog li ntawd, qhov hluav taws xob ntws los ntawm TV yog 0,5 Ampere. Yog tias PLN teeb tsa tus nqi ntawm Rp. 600,00/kWh, ces tus nqi siv TV rau 1 hlis (30 hnub) yog….

A. Rp. 9.900,00

B. Rp. 11.880,00

C. Rp. 19.800,00

D. Rp. 23.760,00

Kev Sib Tham

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Cov khoom siv dot siv cov khoom vector unit

Cov Khoom Siv Dot Multiplication Siv Unit Vector Components

Peb tuaj yeem xam cov khoom scalar ncaj qha yog tias peb paub cov x, y thiab z Cheebtsam ntawm vectors A thiab B (cov vectors paub).

Yuav ua ib qho dot product li no, peb xub ua ib qho dot product ntawm cov unit vectors, tom qab ntawd peb qhia cov vectors A thiab B hauv lawv cov khoom, rhuav tshem cov khoom thiab siv cov khoom ntawm cov unit vectors.

Cov unit vectors i , j, thiab k yog perpendicular rau ib leeg, ua rau kev xam yooj yim dua. Siv cov scalar multiplication equation uas tau los saum toj no ( AB = AB cos theta ), peb tau txais:

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Cov khoom sib txuas siv cov khoom sib txuas ntawm chav tsev vector

Kev Sib Npaug Cov Khoom Siv Siv Cov Cheebtsam Vector Hauv Chav

Peb tuaj yeem xam cov khoom sib tshuam ncaj qha yog tias peb paub cov khoom ntawm cov vectors. Cov txheej txheem zoo ib yam li rau cov khoom dot . Ua ntej, peb muab cov vectors unit i , j , thiab k sib npaug . Cov khoom vector ntawm tib lub vectors unit yog xoom.

i x i = j x j = k x k = 0

Los ntawm kev xa mus rau qhov sib npaug ntawm vector multiplication uas tau muab ua ntej (A x B = AB kev txhaum θ) thiab cov khoom anti-commutative ntawm vector multiplication (A x B =– B x A), ces peb tau txais:

i x j = -j i = k​

j x k = -k x j = i

k x i = – i x k = j

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Chav vector

Nkag Siab Txog Cov Vectors Hauv Chav 

Ib lub vector unit yog ib lub vector uas nws qhov loj yog 1. Ib lub vector unit tsis muaj units thiab ua haujlwm los qhia qhov kev taw qhia hauv qhov chaw. Txhawm rau kom paub qhov txawv ntawm ib lub vector ib txwm, nws raug luam tawm ua ntawv tuab (rau cov ntawv luam tawm) lossis ib lub cim ^ raug ntxig rau saum nws (rau kev sau ntawv).

Hauv Cartesian coordinate system (xyz) peb siv lub unit vector i los qhia qhov kev taw qhia ntawm x-axis zoo, j los qhia qhov kev taw qhia ntawm y-axis zoo, k los qhia qhov kev taw qhia ntawm y-axis zoo.

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Kev sib npaug ntawm kev sib npaug

Qhov khoom sib tshuam ntawm ob lub vectors, piv txwv li vectors A thiab B, yog sau ua A x B ( A hla B ). Cov khoom sib tshuam hu ua vector khoom vim tias qhov tshwm sim ntawm qhov kev sib ntxiv no tsim cov vector ntau.

Piv txwv li, vector A thiab vector B zoo li daim duab hauv qab no.

Kev sib npaug ntawm kab 1Txhawm rau txhais cov khoom sib tshuam ntawm cov vectors A dan B (A x B), peb kos lub vector A dan B raws li tau pom hauv daim duab saum toj no, thiab kuj tau piav qhia cov khoom sib xyaw vector B yog perpendicular rau A, uas yog sib npaug rau B sin theta.

Yog li, peb tuaj yeem txhais qhov loj ntawm cov khoom sib tshuam ntawm cov vectors. A dan B (A x B) ua cov khoom ntawm qhov loj ntawm lub vector A nrog cov khoom vector B perpendicular rau lub vector A.

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Cov khoom cim

Cov vectors tsis yog cov lej ib txwm muaj, yog li ntawd kev sib npaug ib txwm tsis tuaj yeem siv ncaj qha rau lawv. Peb yuav tsum siv kev sib npaug vector. Muaj ob hom kev sib npaug vector: kev sib npaug dot thiab kev sib npaug hla. Kev sib npaug dot kuj tseem hu ua kev sib npaug scalar vim nws tsim cov lej scalar. Kev sib npaug hla kuj tseem hu ua kev sib npaug vector vim nws tsim cov lej vector. Piv txwv li, muaj ob lub vectors, uas yog A dan BKev sib npaug ntawm cov vectors A dan B tau hais nrog AB KVim tias lub arena siv cov cim qhia dot, qhov kev sib npaug no hu ua cov khoom dot. Kev sib npaug ntawm vector A dan B tau hais nrog A x BVim nws siv cov cim qhia x, ces qhov kev sib ntxiv no hu ua kev sib ntxiv hla.

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Cov lus nug txog kev hloov pauv cua sov

3 Cov lus nug txog kev hloov pauv cua sov

1. Saib daim duab hauv qab no!

Yog tias peb lub kav dej raug muab tso rau hauv lub thawv iav kaw raws li pom hauv daim duab. Cov pa luam yeeb los ntawm daim ntawv yob raug muab tso rau ntawm qhov kawg ntawm lub kav dej B thiab nkag mus rau hauv lub kav dej, ces cov pa luam yeeb yuav tawm dua los ntawm cov kav dej A thiab C raws li pom hauv daim duab. Qhov xwm txheej no tshwm sim vim yog kev hloov pauv ntawm cua sov los ntawm….

A. kev sib hloov cua sovLo lus nug txog kev hloov pauv cua sov 1

B. kev sib txuas lus

C. kev qhia

D. kev tawg hluav taws xob

Kev Sib Tham

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