Shin kun taɓa ganin kyandir? da fatan za ku yi amfani da shi. Wani abu mai ban sha'awa da za mu iya gani lokacin da kyandir ke ƙonewa. Ƙasan kyandir mai ƙonewa yawanci yana jike da kakin da aka narke (a kan lagwan). Kasancewar kakin da aka narke a kan lagwan yana nufin kyandir zai iya ƙonewa na dogon lokaci. Me ke sa kakin da aka narke ya matsa sama zuwa lagwan kyandir mai ƙonewa? Za mu iya lura da irin wannan lamari a cikin tocilan.
Abubuwa da yawa masu ban sha'awa a rayuwarmu suna kama da abubuwan da ke faruwa a cikin kyandirori da fitilun mai. Kamar dai ruwan yana da ƙafafu, yana barin shi ya tashi sama. Za ku iya bayyana wannan a kimiyyance? Wani ra'ayi na kimiyyar lissafi wanda zai iya bayyana abubuwan da ke faruwa a cikin kyandirori, fitilun mai, da sauran abubuwan da suka shafi hakan shine capillarity.
Ƙarfin Haɗin kai da Mannewa
Haɗin kai shine ƙarfin jan hankali tsakanin ƙwayoyin halitta na abu ɗaya, yayin da ƙarfin jan hankali tsakanin ƙwayoyin halitta na abubuwa daban-daban ake kira mannewa. Misali, idan muka zuba ruwa a cikin gilashi, haɗin kai yana faruwa ne lokacin da ƙwayoyin ruwa ke jawo hankalin juna, yayin da mannewa ke faruwa lokacin da ƙwayoyin ruwa da ƙwayoyin gilashi ke jawo hankalin juna.
Kusurwar Hulɗa
Kafin mu zurfafa cikin manufar capillarity, dole ne mu fara fahimtar yadda mannewa da haɗin gwiwa ke shafar capillarity. Misali, yi la'akari da ruwa a cikin gilashi. Lokacin da haɗin gwiwa na ƙwayoyin ruwa suka fi ƙarfin mannewa (ƙarfin da ke tsakanin ƙwayoyin ruwa da ƙwayoyin gilashi), saman ruwan zai lanƙwasa sama. Misali na wannan shine lokacin da ruwa yake cikin gilashi. Ana yawan cewa ruwa yana jika saman gilashin. Akasin haka, idan ƙarfin mannewa ya fi ƙarfi, saman ruwan zai lanƙwasa ƙasa. Misali, lokacin da mercury yake cikin gilashi.
Kusurwar da lanƙwasa ta samar ana kiranta kusurwar hulɗa. Idan ƙarfin haɗin ruwan ya fi ƙarfin mannewa, kusurwar hulɗa da aka samar gabaɗaya ƙasa da 90°.o (hoto a). Akasin haka, idan ƙarfin mannewa ya fi ƙarfin haɗin ruwa, to kusurwar hulɗar da aka samu ta fi 90 girma.o (siffa ta b). Ƙarfin mannewa da haɗin kai a ka'ida suna da wahalar ƙididdigewa, amma ana iya auna kusurwar hulɗa. Menene alaƙar da ke tsakanin capillarity?
Manufar Capillarity
Idan ƙarfin haɗin ruwa ya fi ƙarfin mannewa, saman ruwan zai lanƙwasa sama. Lokacin da muka saka bututu ko bututu mai siriri (bututu mai ƙaramin diamita fiye da akwati), wani sashe mafi girma na ruwa zai samar. A wata ma'anar, ruwan da ke cikin akwati yana tashi ta cikin ginshiƙin bututun. Wannan saboda jimillar ƙarfin tashin hankali a saman bangon bututun yana aiki sama. Matsakaicin tsayin da ruwa zai iya kaiwa shine lokacin da ƙarfin tashin hankali a saman ya yi daidai ko daidai da nauyin ruwan da ke cikin bututun. Saboda haka, ruwan zai iya tashi ne kawai zuwa tsayi inda ƙarfin tashin hankali a saman ya daidaita ta hanyar nauyin ruwan da ke cikin bututun.
Akasin haka, idan ƙarfin manne ya fi ƙarfin haɗin ruwan, saman ruwan zai lanƙwasa ƙasa. Lokacin da muka saka bututu ko bututu siriri (bututu mai ƙaramin diamita fiye da akwati), ƙaramin ɓangaren ruwan zai samar (duba hoton da ke ƙasa).
Ana kiran wannan tasirin da motsi na capillary, ko capillarity, kuma waɗannan siririn bututun ana kiransu bututun capillary. Ya kamata a lura cewa ƙananan jijiyoyin jininmu ana iya kiransu bututun capillary, saboda zagayawar jini a cikin waɗannan ƙananan tasoshin shi ma yana faruwa ne saboda tasirin capillary. Hakazalika, abin da ke faruwa na narkewar kakin zuma ko kerosene yana fitowa ta cikin laƙa shi ma a bayyane yake. Bugu da ƙari, ana kyautata zaton capillarity yana taka muhimmiyar rawa a cikin motsin ruwa da abubuwan gina jiki daga tushen zuwa ga ganye ta cikin ƙananan tasoshin xylem. Ba tare da capillarity ba, saman ƙasa zai bushe nan da nan bayan ruwan sama ko ban ruwa. Wani muhimmin tasirin capillarity shine riƙe ruwa a cikin gibin da ke tsakanin barbashi na ƙasa.
Daidaito na Capillarity
Ta yaya za mu iya tantance tsayin ruwan da ke tashi ta cikin ginshiƙin bututun capillary? Ruwan ya bayyana yana tashi a cikin ginshiƙin. 
bututun capillary wanda ke da radius r zuwa tsayi h. Ƙarfin da ke taka rawa wajen riƙe ruwan a tsayi h shine ɓangaren ƙarfin tashin hankali na saman a tsaye: F cos theta.
Saman bututun capillary a buɗe yake, don haka ana yin matsin lamba a saman ruwan. Tsawon saman hulɗa tsakanin ruwan da bututun shine 2 phi r (kewayen da'irar). Saboda haka, girman ɓangaren tsaye na ƙarfin tashin hankali na saman da ke aiki a saman hulɗa shine:
Idan aka yi watsi da lanƙwasa sama na saman ruwan, to yawan ruwan da ke cikin bututun shine:
Ƙarar ruwa = Yankin saman bututu x Tsawon ruwa
V = A h
V = (π r)2) h
Idan bangaren tsaye na Ƙarfin Tashin Sama ya daidaita da nauyin ginshiƙin ruwa a cikin bututun capillary, to ruwan ba zai iya ƙara tashi ba. A wata ma'anar, ruwan zai kai matsakaicin tsayinsa, lokacin da aka daidaita ɓangaren tsaye na ƙarfin tashin saman tare da nauyin ruwan a tsayinsa h. Bangaren tsaye na ƙarfin tashin saman shine:
F = γ 2 π r cos θ
A halin yanzu, nauyin ruwan da ke cikin bututun capillary shine:
w = mg
w = ρ V g
w = ρ ( π r2 h ) g
Idan ruwan ya kai matsakaicin tsayinsa (h), dole ne bangaren tsaye na ƙarfin tashin hankali na saman ya zama daidai da nauyin ruwan a cikin bututun capillary. A lissafi, an rubuta:
Wannan shine lissafin da muke nema. Idan kuna son tantance tsayin ginshiƙin ruwa, da fatan za a yi amfani da wannan lissafin.
