Cov txheej txheem:

Yuav ua li cas koj pom tag nrho qhov chaw ntawm lub tog raj kheej hollow?
Yuav ua li cas koj pom tag nrho qhov chaw ntawm lub tog raj kheej hollow?

Video: Yuav ua li cas koj pom tag nrho qhov chaw ntawm lub tog raj kheej hollow?

Video: Yuav ua li cas koj pom tag nrho qhov chaw ntawm lub tog raj kheej hollow?
Video: Tswv Yexus lub neej thaum pib txug thaum xaus 2024, Kaum ib hlis
Anonim

Ib lub tog raj kheej yog ib qho khoom uas muaj ib qho kev sib xws, voj voog-section

  1. Curved nto cheeb tsam ntawm a lub tog raj kheej = 2 π rh.
  2. Tag nrho cheeb tsam saum npoo ntawm a lub tog raj kheej = 2 π r h + 2 π r2
  3. Curved nto cheeb tsam ntawm ib lub tog raj kheej hollow = 2 π R h + 2 π r h.
  4. Tag nrho thaj tsam ntawm lub tog raj kheej hollow = 2 π R h + 2 π r h + 2 (π R2 - π r2)

Tom qab ntawd, ib tug kuj yuav nug, dab tsi yog lub mis ntawm tag nrho cov saum npoo ntawm lub tog raj kheej hollow?

Cov tag nrho qhov chaw saum npoo ntawm a hollow lub tog raj kheej yog 2π (r1 + r2) (r2 - r1 + h), qhov twg, r1 yog innerradius, r2 yog sab nraud thiab h yog qhov siab.

Tsis tas li ntawd, tag nrho qhov chaw ntawm lub tog raj kheej yog dab tsi? General formula rau lub tag nrho qhov chaw saum npoo ntawm acylinder t. S. A = 2πrh+2πr2.

Kuj nug, ua li cas koj nrhiav tau tag nrho qhov chaw saum npoo ntawm cov yeeb nkab?

Txuas L thiab D rau hauv qab no kev sib npaug rau xam tus thaj chaw saum npoo ntawm cev : 3.14 xL x D. Piv txwv li, yog tias koj muaj a cev nrog rau qhov ntev ntawm 20feet thiab ib txoj kab uas hla ntawm 2 feet, koj yuav tau txais 3.14 x 20 x 2 thiab pom tias qhov thaj chaw saum npoo ntawm cev sib npaug 125.6 square feet.

Tus qauv rau tag nrho qhov chaw saum npoo yog dab tsi?

Qhov chaw saum npoo yog qhov sum ntawm thaj chaw ntawm txhua lub ntsej muag (lossis nto) ntawm 3D duab. Ib lub cuboid muaj 6 daim duab plaub. Peb tuaj yeem sau qhov ntev (l), qhov dav (w), thiab qhov siab (h) ntawm qhov prism thiab siv qhov qauv , SA=2lw+2lh+2hw, to findthe thaj chaw saum npoo.

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