Chinyorwa pamusoro pekumanikidzwa mumvura
In fizikisi, kumanikidzwa kunotsanangurwa sesimba pachikamu chimwe nechimwe, uko kutungamira kwesimba kwakatarisana nenzvimbo yepamusoro. Pamasvomhu, kumanikidzwa kunoratidzwa ne equation P = F / A, apo P = kumanikidzwa, F = simba uye A = nzvimbo yepamusoro. Chikamu chesimba (F) ndiNewton (N), chikamu chenzvimbo ndicho mita yeskweya (m).2Nekuti kumanikidzwa isimba pachikamu chimwe nechimwe, chikamu chekumanikidzwa iN/m2Rimwe zita rekuti N/m2 ndiPascal (Pa). Pascal aishandiswa sechikamu chekumanikidza kukudza Blaise Pascal.
Kana mvura yakamira, mvura yacho inopa simba rakamira pamusoro pese pekubata. Semuenzaniso, tinoongorora mvura iri mugirazi; chikamu chimwe nechimwe chemvura chinopa simba rine gwara rakamira pamadziro egirazi. Saka chikamu chimwe nechimwe chemvura chinopa simba rakamira panzvimbo yega yega yemudziyo wainogara. Ichi chimwe chezvinhu zvakakosha zvemvura isingachinji. Kana mvura ikashandisa simba rekuita pamusoro, uko gwara resimba risiri rakamira, pamusoro payo pachapa simba rekuita iro gwara risiri rakamira. Izvi zvichaita kuti mvura iyerere. Asi furuu, id iri pakamira. Saka mhedziso ndeyekuti, mumvura isingachinji, gwara resimba rinogara rakamira pamusoro pemudziyo.
Chimwe chinhu chakakosha chemvura isingachinji ndechekuti mvura inogara iine kumanikidzwa kwese kwese. Kuti unzwisise tsananguro iyi zviri nani, isa chinhu chinogona kuyangarara mumvura chiri mumudziyo. Kana mvura yakamira, zvinoreva kuti chinhu chacho hachisi kufamba nekuti kumanikidzwa kwakafanana kunoshanda pamusoro pechinhu chose. Kana kumanikidzwa kwemvura kusina kufanana, saka pachava nesimba rese, iro richaita kuti chinhu chacho chifambe.
Mhedzisiro yekudzika kwemvura pakumanikidzwae
Kudzika kana kukwirira kunokanganisa sei kumanikidzwa kwemvura? Kumanikidzwa kwemvura yegungwa pakadzika kwemamita gumi kwakafanana here nekumanikidzwa kwemvura yegungwa pakadzika kwemamita zana? Ngationgororei kumanikidzwa kwemvura mumudziyo sezvakaratidzwa mumufananidzo. Kureba kwekoramu yemvura ndi h uye nzvimbo yepakati pechikamu A. Chii chinonzi kumanikidzwa kwemvura pasi pemudziyo?
w = huremu hwemvura, h = kureba kwekoramu yemvura mumudziyo wakaita sedenderedzwa, A = nzvimbo yepamusoro, uye P idzvinyiriro.
Huremu hwekoramu yemvura ndeiyi:
ρ = m / V
m = ρ V
m = ρ h A
Kurema kwekoramu yemvura ndeiyi:
w = mg = ρ h A g
w = huremu, ρ = kuwanda, m = huremu, g = kukurumidza kwegiravhiti, V = h A = huwandu hwemvura (h = kureba, A = nzvimbo yepamusoro)
Kana equation iri pamusoro ikaiswa mu equation yekumanikidzwa:
p = ρ gh → Equation 1 (mudziyo wakavharwa)
p = pa + ρ gh → Equation 2 (mudziyo wakavhurika)
pa = kumanikidzwa kwemhepo, ρ gh = kumanikidzwa kwemvura
Kana mudziyo wakavhurika uine mvura, kumanikidzwa kwemhepo kunonanga pasi pamusoro pemvura.
Zvichibva paequation iri pamusoro apa, kumanikidzwa kwacho kwakanangana nehuremu uye kudzika kwemvura (gravity acceleration is consistent).
Kana musiyano wehurefu hwakakura (semuenzaniso mumvura yakadzika yegungwa), huwandu hwemvura hunosiyana zvishoma. Asi kana musiyano wehurefu usina kunyanya kukosha, huwandu hwemvura hwakafanana, kana kuti musiyano wacho mudiki zvekuti hautarisirwi.
Tinogona zvakare kushandisa equation iri pamusoro kuti tiverenge musiyano wekumanikidzwa pahudzamu hwakasiyana. Equation iri pamusoro yakanyorwa zvakare:
Δp = ρ g Δh
Δp = musiyano mukumanikidzwa, Δh = musiyano pakukwirira
Kudzvinyirira Atmospheric
Patinonyura mumvura, zvikamu zvese zvemuviri wedu zvinofukidzwa nemvura. Patinonyura zvakadzama, ndipo patinonzwa kumanikidzwa kukuru. Zuva rega rega tinofukidzwawo nemhepo inogara ichidzvinyirira zvikamu zvese zvemuviri wedu sepatinenge tiri mumvura. Sezvakaita mumvura yegungwa, pamusoro penyika panogona kufananidzwa nemhepo "yakavakirwa pagungwa". Kana mhepo ichidzvinyirira zvikamu zvese zvemuviri wedu chero nguva, sei tisingazvinzwi, sekunge tiri pasi pegungwa? Masero emuviri wedu anochengetedza kumanikidzwa kwemukati kwakada kufanana nekumanikidzwa kwekunze. Izvi zvinoita kuti tisanzwe mhedzisiro yekusiyana uku kwekumanikidzwa.
Kumanikidzwa kwemhepo yepasi kunochinjawo nekukwirira. Asi kumanikidzwa kwemhepo yepasi kunosiyana nemvura. Kuchinja kwehuwandu hwemvura kudiki kwazvo kana tichitarisa musiyano wehudzamu husiri hukuru zvakanyanya zvekuti huwandu hwemvura hunoonekwa sehwakafanana. Izvi zvakasiyana nehuremu hwemhepo yepasi. Huremu hwemhepo yepasi hunosiyana zvakanyanya nekukwirira. Huremu hwemhepo pakukwirira kwega kwega hunosiyana zvekuti hatigone kuverenga kumanikidzwa kwemhepo tichishandisa maequation akawanikwa pamusoro apa. Zvakare, hapana muganho pamhepo iyo kukwirira kunogona kuyerwa nayo. Kumanikidzwa kwemhepo kunosiyanawo nemamiriro ekunze. Kuti tizive kumanikidzwa kwemhepo, tinotora zviyeros.
Kuyerwa kweDzvinyiriro
Evangelista Torricelli (1608-1647), mudzidzi waGalileo, akagadzira nzira yekuyera kumanikidzwa kwemhepo muna 1643 achishandisa mercury barometer yebasa rake. Barometer ichubhu refu yegirazi, umo chubhu inozadzwa nemercury. Zvakanaka, chubhu yegirazi ine mercury inodzoserwa mundiro yakazadzwawo nemercury.
Kana pombi yegirazi ine mercury ikadzoserwa kumashure, mugumo wepombi hauzadzwe nemercury; zviri mukati inongova mercury vapor, kumanikidzwa kudiki zvekuti hakuonekwi (p2 = 0). Pamusoro pemercury iri mukati meplate, pane kumanikidzwa kwemhepo kunonangidzirwa pasi (mhepo inodzvanya mercury iri paplate). Kumanikidzwa kwemhepo kunobata mercury column mupombi yegirazi. Mumufananidzo, kumanikidzwa kwemhepo kunomiririrwa ne po. Huwandu hwekumanikidzwa kwemhepo hunogona kuverengerwa uchishandisa equation:
po = ρ gh
Zvichibva pamhedzisiro yekuyerwa, avhareji yekumanikidzwa kwemhepo padanho regungwa i1.013 x 105 N / m2Huwandu hwekumanikidzwa kwemhepo pagungwa hunoshandiswa kutsanangura mamwe mayuniti ekumanikidzwa, kureva atm (mhepo). Saka 1 atm = 1.013 x 105 N / m2 = 101.3 kPa (kPa = kilo pascals). Imwe pressure unit ibar (inowanzoshandiswa mu meteorology). 1 bar = 1.00 x 105 N / m2 = 100 kPa.
Kumanikidzwa kwemhepo iri pamusoro apa kunowanikwa sei?
Kuyera kunoshandisa misimboti yakaratidzwa naTorricelli pamusoro apa. Kureba kwechikamu chemercury chinoshandiswa i76 cm (kumanikidzwa kwemhepo kunogona kungobata chikamu chemercury chinosvika 76.0 cm chete pakureba), apo tembiricha yemercury inoshandiswa chaizvo 0 oC uye hukuru hwekukurumidzira kwegiravhiti ndeye 9.8 m/s2Huremu hwemercury mumamiriro ezvinhu aya i13.6 x 103 kg / m3Kumanikidzwa kwemhepo:
po = ρ gh
po = (13.6 x 103 kg / m3)(9.8 m/s2)(76 cm)
po = (13.6 x 103 kg / m3)(9.8 m/s2)(76 x 10-2 m)
po = 101.3 x gumi3 N / m2
po = 1.013 x gumi5 N / m2
po = 1 atm
Pressure midziyo
Kune maturusi akawanda anoshandiswa kuyera kumanikidzwa, kusanganisira ma manometer echubhu yakavhurika.
Mumuchina wepaipi wakavhurika, apo pipi yacho yakaita seU, mamwe machubhu anozadzwa nemvura (mercury kana mvura). Kumanikidzwa kwakayerwa kunobatanidzwa nemusiyano uri pakati pehurefu huviri hwemvura inozadzwa mupipi. Huwandu hwekumanikidzwa hunoverengerwa uchishandisa equation:
p = pa + ρ gh
pa = kumanikidzwa kwemhepo
ρ gh = kumanikidzwa kwakayerwa
ρ = kuwanda kwemvura
Kazhinji hazviverengerwi chigadzirwa ρ gh asi kukwirira kwemvura (h) nekuti kumanikidzwa dzimwe nguva kunoratidzwa mumamirimita emercury (mm Hg) kana mamirimita emvura (mm H2Oh). Rimwe zita rekuti mm hg nditorr (mukuremekedza Evangelista Torricelli).
Pamusoro pemanometers, kunewo mamwe magauge anoti aneroid barometers, ese ari maviri emakanika neemagetsi, kusanganisira magauge epressure yematairi, nezvimwewo. Chishandiso chinoshandiswa naTorricelli kuyera pressure yemumhepo chinonziwo mercury barometer, umo chubhu yegirazi inozadzwa nemercury.
Kumanikidzwa kweGauge uye Kumanikidzwa Kwakazara
Kumanikidzwa kwakakwana = kumanikidzwa kwemhepo + kumanikidzwa kwakayerwa. Saka kuti tiwane kumanikidzwa kwakakwana, takawedzera geji kumanikidzwa nemhepo inomanikidza. Nemamwe mashoko, kumanikidzwa kwakakwana = kumanikidzwa kwakazara. Zvinogona kunyorwa nemasvomhu:
p = pa + pg
Semuenzaniso kana kumanikidzwa kwetai kwatinoyera = 100 kPa, saka kumanikidzwa kwakakwana ndekwekuti:
p = pa +pg
p = 101 kPa + 100 kPa
p = 201 kPa
Huwandu hwekumanikidzwa kwakakwana = 201 kPa
Muenzaniso wedambudziko 1:
Ngarava yemugungwa inonyura kusvika pakadzika kwemamita mazana maviri. Simba remugungwa rinomanikidzwa zvakadini? g = 10 m/s2
Zvinozivikanwa:
Kudzika (h) = 200 m
Kuwanda kwemvura yegungwa (ρ) = 1.03 x 103 kg / m3 = 1030 kg / m3
Kumanikidzwa kwemhepo (pa) = 1 atm = 1 x 105 N / m2 = 1 x gumi5 (Kg m/s2)/m2 = 1 x gumi5 Kg/ms2
Kukurumidza kwegiravhiti (g) = 10 m/s2
Zvaidiwa:
Solution:
p = pa + ρ gh
p = 1 x 105 kg/ms2 + (1030 kg/m23)(10 m/s2(200 m)
p = 1 x 105 kg/ms2 + 2060000 kg/ms2
p = 1 x 105 kg/ms2 + 20.6x105 kg/ms2
p = 21.6 x 105 kg/ms2
p = 21.6 x 105 N / m2
p = 21.6 x 105 Pa
Chirongo chakavhurika kuitira kuti kumanikidzwa kwemhepo kusasanganisirwe mukuverenga.
Muenzaniso wedambudziko 2:
Dziva remvura Rizere nemvura ine urefu hwemamita gumi. Kana pamusoro pedziva remvura pakavharwa, simba remvura riri pasi pemudziyo nderei? g = 10 m/s2
Zvinozivikanwa:
Kureba (h) = 10 m
Kuwanda kwemvura (ρ) = 1,00 x 103 kg / m3 = 1000 kg / m3
Kumanikidzwa kwemhepo (pa) = 1 atm = 1 x 105 N / m2 = 1 x gumi5 (kg m/s2) / m2 = 1 x gumi5 Kg/ms2
Kukurumidza kwegiravhiti (g) = 10 m/s2
Zvaidiwa: Pressure
Solution:
p = ρ gh
p = (1000 kg/m3)(10 m/s2(200 m)
p = 2000,000 kg/ms2
p = 20 x 105 kg/ms2
p = 20 x 105 N / m2
p = 20 x 105 Pa
Mudziyo wacho wakavharwa kuitira kuti kumanikidzwa kwemhepo kusasanganisirwe mukuverenga.
Muenzaniso wedambudziko 3:
Kureba kwekoramu yemvura (kurudyi) = 50 cm, ukuwo kukwirira kwekoramu yemvura (kuruboshwe) = 30 cm. Kuwanda kwezvimwe zvinwiwa chii?
Zvinozivikanwa:
Kukurumidza kwegiravhiti (g) = 10 m/s2
Kureba kwemvura (h)1) = 50 cm
Kuwanda kwemvura (ρ)1) = 1 x 103 kg / m3 = 1000 kg / m3
Kureba kwechimwe chinwiwa (h2) = 30 cm
Zvaidiwa: Kuwanda kwechimwe chinwiwa
Solution:
pa + ρ1 gh1 = pa + ρ2 gh2
ρ1 h1 = ρ2 h2
ρ2 = ρ1 h1 / h2
ρ2 = (50 cm)(1000 kg/m3) / 30 cm
ρ2 = 1666.7 kg / m3
