I-Capillarity

Amandla Okubumbana Nokunamathela

Amandla okubumbana amandla okubumbana phakathi kwama-molecule entweni efanayo, kuyilapho amandla okubumbana phakathi kwama-molecule ento engalingani abizwa ngokuthi Amandla Okubumbana. Isibonelo, sithela amanzi engilazini. Ukubumbana kwenzeka lapho ama-molecule amanzi edonselana, kuyilapho ukunamathelana kwenzeka lapho ama-molecule amanzi nama-molecule engilazi edonselana.

I-engeli yokuxhumana

Ngaphambi kokufunda umqondo we-Capillarity, siqala siqonde ukuthi ithonya lamandla okunamathela kanye namandla okunamathelana lithinta kanjani i-capillarity. Isibonelo, sibuyekeza uketshezi olusengilazini. Lapho amandla okunamathelana kwe-molecule ewuketshezi enamandla kunamandla okunamathelana (amandla okudonsa phakathi kwe-molecule ewuketshezi kanye ne-molecule yengilazi) ubuso boketshezi buzokwakha ijika eliya phezulu. Isibonelo salokhu yilapho amanzi esengilazini. Ngokuvamile, kuthiwa amanzi acwilisa ubuso bengilazi. Ngokuphambene nalokho, uma amandla okunamathela enamandla, khona-ke ubuso boketshezi buzogoba phansi. Isibonelo, lapho i-mercury isengilazini.

I-engeli eyakhiwe yi-curve ibizwa ngokuthi i-contact angle. Uma amandla okuhlangana koketshezi ephakeme kunamandla okunamathela, i-engeli yokuxhumana eyakhiwe ngokuvamile incane kuno-90^o (isibalo a). Ngokuphambene nalokho, uma amandla okunamathela ephakeme kunamandla okubumbana koketshezi, i-engeli yokuxhumana eyakhiwe inkulu kune-90^o (isithombe b). Amandla okunamathela kanye namandla okuhlangana kunzima ukuwabala ngokombono, kodwa ama-engeli okuxhumana angalinganiswa. Kuhlobene kanjani nobukhulu be-capillarity?

Umqondo we-Capillarity

Uma amandla okuhlangana koketshezi makhulu kunamandla okunamathela, ubuso boketshezi buzogoba bubheke phezulu. Uma sifaka ipayipi elincane noma ipayipi (ipayipi elinobubanzi obuncane kunesitsha), uketshezi olusesitsheni lukhuphuka ngekholomu yepayipi. Lokhu kungenxa yokuthi amandla okucindezeleka okuphelele kobuso odongeni lwepayipi asebenza phezulu. Ukuphakama okuphezulu okungafinyelelwa uketshezi yilapho amandla okucindezeleka kobuso elingana nesisindo soketshezi olusepayipini. Ngakho-ke, uketshezi lungakhuphukela kuphela ekuphakameni lapho amandla okucindezeleka kobuso elinganiswa nesisindo soketshezi olusepayipini.

Ngakolunye uhlangothi, uma amandla okunamathela makhulu kunamandla okubumbana koketshezi, ubuso boketshezi buzogoba buyehla. Uma sifaka ipayipi elincane noma ipayipi (ipayipi elinobubanzi obuncane kunesitsha), lizokwakha ingxenye engezansi yoketshezi (bheka isithombe ngezansi).

Lo mphumela waziwa ngokuthi i-capillary, kanti ipayipi elincane libizwa ngokuthi i-capillary tube. Khumbula ukuthi imithambo yethu yegazi emincane kakhulu ingabizwa nangokuthi amapayipi e-capillary ngoba ukujikeleza kwegazi emithanjeni yegazi emincane nakho kwenzeka ngenxa yemiphumela ye-capillary. Ngokufanayo, isimo sokuncibilika kwe-wax noma i-parafini ekhuphukayo nge-axis. Ngaphezu kwalokho, i-capillarity nayo ikholakala ukuthi idlala indima ebalulekile ekudluleni kwamanzi nezinto ezinempilo kusukela ezimpandeni kuya emaqabunga ngemithambo ye-xylem. Uma kungekho capillarity, ubuso bomhlabathi buzokoma ngokushesha ngemva kwemvula. Omunye umphumela obalulekile we-capillarity ukugcinwa kwamanzi ezikhaleni eziphakathi kwezinhlayiya zomhlabathi.

Isibalo se-Capillarity

Singakuthola kanjani ukuphakama kwamanzi akhuphuka ngekholomu yepayipi le-capillary? Ukuphakama koketshezi kwikholomu yepayipi le-capillary, ene-radius r kuze kufike ekuphakameni h. Amandla asebenza ekubambeni uketshezi ekuphakameni h ayingxenye yamandla okucindezela ubuso ohlangothini oluqondile: F cos θ.

Ingxenye ephezulu yepayipi le-capillary ivulekile ukuze kube nokucindezela komoya ebusweni boketshezi. Ubude bomphezulu wokuthinta phakathi koketshezi nepayipi bungu-2πr (ukuzungeza). Ngakho-ke, ubukhulu bamandla okucindezela kobuso bezingxenye eziqondile ezisebenza ebusweni bokuxhumana yilezi:

F = Amandla okucindezela ubuso, γ = Ukucindezela ubuso, r = irediyasi yepayipi le-capillary, θ = I-engeli yokuxhumana

Uma indawo egobile phezulu inganakwa, umthamo woketshezi olusepayipini uwukuthi:

Umthamo woketshezi = indawo engaphezulu kwepayipi x ukuphakama koketshezi

V = A h

V = (π r ² ) h

Uma ingxenye eqondile ye-Surface Tension Force ilinganiswa nesisindo sekholomu yoketshezi ku-capillary tube, khona-ke uketshezi alukwazi ukuvuka futhi. Ngamanye amazwi, uketshezi luzofinyelela ukuphakama kwalo okuphezulu, uma ingxenye eqondile ye-surface tension force ilinganiswa nesisindo soketshezi, kuze kufike ku-h. Ingxenye eqondile ye-surface tension force yile:

F = γ 2 π r cos θ

Ngenkathi isisindo soketshezi olusepayipini le-capillary singu:

w = mg

w = ρ V g

w = ρ (π r ² h) g

Uma uketshezi lufinyelela ukuphakama kwalo okuphezulu (h), ingxenye eqondile yamandla okucindezela ubuso kumele ilingane nesisindo soketshezi olusepayipini le-capillary. Ngokwezibalo, kubhaliwe:

Lesi yisibalo esisifunayo. Uma ufuna ukuthola ukuphakama kwekholomu yoketshezi, sicela ucabangele ukusebenzisa lesi sibalo.