Video: Lub ntsej muag zoo li cas muaj 5 lub ntsej muag?
2024 Tus sau: Miles Stephen | [email protected]. Kawg hloov kho: 2023-12-15 23:36
Hauv geometry, pentahedron (plural: pentahedra) yog polyhedron nrog tsib lub ntsej muag lossis sab. Tsis muaj lub ntsej muag-transitive polyhedra nrog tsib sab thiab muaj ob hom topological txawv. Nrog lub ntsej muag polygon tsis tu ncua, ob daim ntawv topological yog cov square pyramid thiab daim duab peb sab prism.
Ib yam li ntawd, daim duab twg muaj 5 lub ntsej muag?
Lawv muaj ob hom pyramids daim duab peb sab thiab square. Lub square pyramid muaj 5 lub ntsej muag, 8 ntug, thiab 5 vertices. Cov daim duab peb sab pyramid muaj 4 lub ntsej muag, 8 ntug, thiab 4 vertices.
Ib yam li ntawd, polyhedral zoo li cas? Peb-dimensional puab nws lub ntsej muag yog polygons hu ua a polyhedron . Lo lus no los ntawm Greek lo lus poly, uas txhais tau tias "ntau," thiab hedron, uas txhais tau tias "lub ntsej muag." Yog li, qhov tseeb, a polyhedron yog ib yam khoom peb-dimensional nrog ntau lub ntsej muag. Lub ntsej muag ntawm lub voos xwmfab yog squares.
Ua kom pom qhov no, 20 lub ntsej muag zoo li cas hu ua?
Nyob rau hauv geometry, ib tug icosagon los yog 20 -gon yog nees nkaum- sab polygon . Qhov sib npaug ntawm txhua lub icosagon lub kaum sab hauv yog 3240 degrees.
Dab tsi yog qhov siab tshaj sab zoo?
Rhombicosidodecahedron. Nyob rau hauv geometry, lub rhombicosidodecahedron, yog ib tug Archimedean khoom, ib tug ntawm kaum peb convex isogonal nonprismatic solids tsim los ntawm ob los yog ntau tshaj li niaj zaus. polygon ntsej muag. Nws muaj 20 lub ntsej muag daim duab peb sab, 30 lub ntsej muag square, 12 lub ntsej muag pentagonal, 60 vertices, thiab 120 npoo.
Pom zoo:
Lub cylinder muaj pes tsawg lub ntsej muag?
3 fim Tsis tas li ntawd, lub tog raj kheej puas muaj lub ntsej muag? Tag nrho cov duab no yog nkhaus hauv qee way, zoo tsis muaj ntug los yog vertices. Yuav ua li cas txog lawv ntsej muag ? Ib tug kheej kheej tsis muaj ntsej muag ,ib cone muaj ib ncig ntsej muag , thiab a cylinder muaj ob lub voj voog ntsej muag .
Dab tsi yog qhov flux los ntawm ib lub ntsej muag ntawm lub voos xwmfab?
Teb thiab piav qhia: Cov hluav taws xob flux los ntawm ib sab ntawm ib lub voos xwmfab vim yog tus nqi taw tes yog & rho tawm; 32000 V ⋅ m − 32 000 V ⋅ m
Yuav ua li cas yog qhov tshwm sim uas ib tug poj niam dig muag xim uas yuav ib tug txiv neej uas tsis pom kev zoo yuav muaj xim dig muag me nyuam?
Yog tias tus poj niam uas muaj lub zeem muag zoo li no (heterozygous rau qhov muag tsis pom xim) yuav ib tug txiv neej ib txwm muaj (XY), cov xeeb ceem hauv qab no tuaj yeem xav tau hauv F2 tiam: ntawm cov ntxhais, 50% yog ib txwm muaj thiab 50% yog cov neeg nqa khoom rau cov kab mob; ntawm cov tub, 50% yog xim dig muag thiab 50% yog qhov pom kev zoo
Yuav ua li cas muaj pes tsawg tus ntug polyhedron uas muaj plaub lub ntsej muag thiab plaub vertices?
Yog hais tias cov khoom yog polyhedron, npe nws thiab nrhiav tus naj npawb ntawm lub ntsej muag, ntug thiab vertices nws muaj. Lub hauv paus yog daim duab peb sab thiab txhua sab yog daim duab peb sab, yog li qhov no yog daim duab peb sab pyramid, uas tseem hu ua tetrahedron. Muaj 4 lub ntsej muag, 6 ntug thiab 4 ntsug
Koj pom thaj tsam ntawm lub ntsej muag siv lub ntsej muag li cas?
Qhov chaw saum npoo yog qhov sib npaug ntawm thaj chaw ntawm txhua lub ntsej muag (lossis qhov chaw) ntawm 3D duab. Ib lub cuboid muaj 6 lub ntsej muag. Txhawm rau nrhiav thaj chaw saum npoo ntawm lub cuboid, ntxiv cov cheeb tsam ntawm tag nrho 6 lub ntsej muag. Peb tseem tuaj yeem sau qhov ntev (l), dav (w), thiab qhov siab (h) ntawm lub prism thiab siv cov qauv, SA = 2lw + 2lh + 2hw, txhawm rau nrhiav thaj chaw saum npoo