Video: Yuav ua li cas koj nrhiav tau tag nrho saum npoo ntawm ib tug kheej kheej?
2024 Tus sau: Miles Stephen | [email protected]. Kawg hloov kho: 2023-12-15 23:36
Yuav nrhiav tau thaj tsam ntawm ib lub sphere , siv qhov sib npaug 4πr2, qhov twg r stands rau lub vojvoog, uas koj yuav muab nws tus kheej rau square nws. Tom qab ntawd, muab cov squared radius los ntawm 4. Piv txwv li, yog tias lub vojvoog yog 5, nws yuav yog 25 x 4, uas sib npaug 100.
Nyob rau hauv tas li ntawd, dab tsi yog lub formula rau tag nrho cov saum npoo ntawm ib tug kheej kheej?
Ib yam li ntawd, qhov ntim ntawm a pob enclosed ib kheej kheej ntawm lub vojvoog R yog (4/3) * Pi * R3. Thiab cov qauv rau cov thaj tsam ntawm ib lub sphere Lub vojvoog R yog 4 * Pi * R2. Thiab, koj tuaj yeem tshawb xyuas tias qhov tom kawg yog qhov derivative ntawm tus qub nrog rau R.
Tom qab ntawd, lo lus nug yog, yog vim li cas thiaj muaj 4 nyob rau hauv qhov chaw ntawm ib tug kheej kheej? Ib qho kev piav qhia geometric yog qhov ntawd 4 π r2 yog derivative ntawm 4 3πr3, qhov ntim ntawm lub pob nrog lub vojvoog r, nrog rau r. Qhov no yog vim hais tias yog koj loj r me ntsis, lub ntim ntawm lub pob yuav hloov los ntawm nws nto lub sij hawm qhov loj me ntawm r.
Tom qab ntawd, tus qauv rau kev nrhiav tus kheej yog dab tsi?
Yuav xam cov ntim ntawm ib tug kheej kheej, siv cov mis v = 4⁄3πr³, qhov twg r yog lub vojvoog ntawm tus kheej. Yog tias koj tsis muaj lub vojvoog, koj tuaj yeem pom nws los ntawm kev faib txoj kab uas hla ntawm 2. Thaum koj muaj lub vojvoog, ntsaws rau hauv cov qauv thiab daws kom pom qhov ntim.
Qhov chaw ntawm lub hemisphere yog dab tsi?
Yog tias koj muaj ib qho khoom hemispherical ces nws muaj lub hauv paus uas yog lub voj voog ntawm lub voj voog r. Cov cheeb tsam ntawm lub voj voog ntawm lub voj voog r yog π r2 thiab yog li ntawd yog cov hemisphere yog meant suav nrog lub hauv paus ces tus thaj chaw saum npoo yog 2r2 + np r2 = 3 π r2.
Pom zoo:
Yuav ua li cas koj nrhiav tau qhov chaw saum npoo ntawm ib qho khoom?
Txhawm rau nrhiav thaj chaw saum npoo ntawm lub prism (los yog lwm yam geometric khoom) peb qhib cov khoom zoo li lub thawv ntawv thiab flatten nws tawm kom pom tag nrho cov ntawv geometric. Txhawm rau nrhiav qhov ntim ntawm lub prism (nws tsis muaj teeb meem yog tias nws yog duab plaub lossis duab peb sab) peb muab cov cheeb tsam ntawm lub hauv paus, hu ua thaj tsam B, los ntawm qhov siab h
Yuav ua li cas koj sau ib feem raws li ib tug khoom ntawm ib tug tag nrho cov zauv thiab ib feem feem?
Cov cai los nrhiav cov khoom ntawm ib feem feem thiab tag nrho tus lej Peb xub sau tag nrho cov lej ua ib feem, piv txwv li, sau nws faib los ntawm ib qho; Piv txwv li: 7 yog sau ua 71. Peb mam li muab cov zauv. Peb muab cov denominators. Yog tias yuav tsum tau ua kom yooj yim, nws ua tiav thiab tom qab ntawd peb sau cov feem kawg
Yuav ua li cas yog lub sum ntawm cov atomic masses ntawm tag nrho cov atoms nyob rau hauv ib tug qauv rau ib tug compound?
Cov mis loj ntawm ib yam khoom yog qhov sib npaug ntawm qhov nruab nrab atomic masses ntawm txhua lub atom sawv cev hauv cov tshuaj formula thiab qhia nyob rau hauv atomic mass units. Cov mis loj ntawm covalent compound tseem hu ua molecular mass
Yuav ua li cas yog ib tug piv txwv ntawm ib tug rational naj npawb uas tsis yog ib tug tag nrho?
Tus lej "rational" yog qhov piv ntawm ob tus lej. Piv txwv li, cov hauv qab no yog cov lej rational, thiab tsis muaj leej twg yog tus lej: 1 / 2. 2 / 3
Yuav ua li cas koj nrhiav tau qhov chaw saum npoo thiab ntim ntawm ib lub voj voog?
Qhov chaw saum npoo = (2 • π • r²) + (2 • π • r • qhov siab) Qhov twg (2 • π • r²) yog thaj tsam ntawm 'kawg' thiab (2 • π • r • siab ) yog thaj chaw sab nraud ( thaj tsam ntawm 'sab')