Buoyancy karfi

Bari mu yi wani sauki gwajin: kai dan kadan inflated roba ball da kuma "imbedded" a ruwa. Idan nutsewa zurfi ne ko 1-2 mita, shi ne mai sauki ga cewa ta girma an rage, watau, a kan dukkan bangarorin da ball zai crimp wasu da karfi. A mafi yawa ana ce cewa akwai "m" hydrostatic matsa lamba - A zahirin sojojin aiki a kan keken ruwaye nutsa jiki. Hydrostatic sojojin aiki a jiki daga duk tarnaƙi, kuma su resultant, da aka sani da Archimedes karfi, har yanzu da ake kira ejection, wanda yayi dace da shugabanci na tasirinta a jiki na nutsa cikin wani ruwa.

Archimedes gano ya dokar zalla gwaji, kuma ta msar tambayar gaskata jira domin kusan shekaru 2,000 kafin Pascal ya gano dokar hydrostatics for tsit ruwa. A cewar wannan dokar, da matsa lamba daukar kwayar cutar ta hanyar da ruwa a duk inda ko da kuwa yankin a kan wanda shi abubuwa a kan duk jirage bounding cikin ruwa, da kuma muhimmancinsa ne na gwargwado ga surface P da S tare da al'ada, a nan. Pascal buɗe, da kuma bari da doka a kan kwarewa a 1653. A cewar shi, a kan surface wani jiki na nutsa cikin ruwa a kan dukkan bangarorin da hydrostatic matsa lamba.

Ɗauka cewa jirgin ruwa da ruwa a cikin wani nau'i na jiki nutsa shigen sukari zurfin H to L - nesa daga ruwa surface zuwa saman fuska. Lokacin da wannan ƙananan mamaye ne ga zurfin H + L. A karfi vector F1, mukaddashin a kan babba fuska ne directed zuwa ƙasa, kuma F1 = r * g * H * S, inda r - ruwa yawa, g - hanzari nauyi.

A vector karfi F2, exerted a kan ƙananan jirgin sama, kuma da darajar da aka ba ta F2 = r * g * (H + L) * S.

A vectors na sojojin aiki a kan gefen saman yardatayya daidaita, don haka baya cire daga shawara. Buoyancy karfi F2> F1 da directed daga kasa zuwa top, kuma a haɗe zuwa kasa fuskar shigen sukari. Ƙayyade da darajar F:

F = F2 - F1 = r * g * (H + L) * S - r * g * H * S = r * g * L * S

Lura cewa L * S - .. Shin ƙara da wani shigen sukari V, kuma m ga r * g = p wakiltar ruwa nauyi naúrar, sa'an nan da dabara nauyi na Archimedean karfi kayyade girma na ruwa, sunã daidaita da girma na shigen sukari, Ina nufin Wannan shi ne daidai da nauyin da ruwa gudun hijira da jiki. Yana da ban sha'awa ga magana game da Archimedes 'manufa mai yiwuwa ne kawai ga muhalli, inda a can ne karfi na nauyi - a yanayi na weightlessness, dokar ba ya aiki. A karshe, cikin dabara na dokar Archimedes ne kamar haka:

F = p * V, inda p - ruwa musamman nauyi.

Archimedean karfi zai iya zama a matsayin tushen ga bincike na buoyancy jikinsu. A yanayin for analysis ne rabo daga cikin nauyi jiki ɗora Kwatancen pm da kuma PF nauyi ruwa tare da wani ƙarfi daidaita da girma na nutsa cikin ruwa jiki. Idan PM = px, jiki iyo a cikin ruwa, da kuma idan K.Mag> PF, jiki sinks. In ba haka ba, jikin fitowa kamar buoyant karfi daidai da nauyin da fitad da recessed rabo daga ruwa jiki.

Archimedes 'manufa da kuma yin amfani yana da dogon tarihi a fasaha, da suka fara da classic misali na yin amfani da duk aka sani da iyo wuraren zuwa balloons da airships. Ga shi da wani matsayi da cewa gas tana nufin wani Jihar al'amari cewa shi ne quite m simulates. Saboda haka, a cikin iska yanayi ga wani abu buoyancy karfi aiki mai kama guda kamar yadda a cikin ruwa. A farko yunkurin gudanar da iska balan-balan jirgin dauki Montgolfier 'yan'uwa - sun cika da balan-balan tare da dumi hayaki, don haka da cewa nauyin wani fursuna a wani iska balan-balan ya kasa da nauyi na wannan girma na sanyi iska. Wannan ne dalilin da daga, da kuma da darajar da aka bayyana a matsayin bambanci a cikin nauyi na biyu kundin. A ci gaba da kyautata ya balloons kuka, wanda ci gaba da heats iska ciki da balan-balan. A fili yake cewa da iyaka da dogara a kan tsawon na kuka. Daga baya a kan airships amfani ga ciko a gas tare da wani takamaiman nauyi kasa da cewa daga iska.