1. Incazelo yamandla okungqubuzana
Ukungqubuzana kuwukuhudula okusebenza phakathi kwezinto ezithintanayo. Kulesi sihloko, amandla okungqubuzana afundwe ahlobene namandla okungqubuzana asebenza phakathi kwezindawo ezimbili zomzimba eziqinile ezithintanayo. Njengokungqubuzana phakathi kwesisekelo sogongolo kanye nobuso bephansi, ukungqubuzana phakathi kwesisekelo sezicathulo kanye nobuso bephansi, ukungqubuzana phakathi kwamasondo emoto kanye nobuso bomgwaqo.
Amandla okungqubuzana ahlala esebenza ebusweni bezinto eziqinile ezithintana, noma ngabe izinto zibushelelezi kakhulu. Ngisho nezindawo ezibushelelezi empeleni zilukhuni kakhulu esikalini esincane kakhulu. Lapho into ihamba, lezi zingqimba ezincane kakhulu ziphazamisa ukunyakaza. Ezingeni le-athomu, ukuphuma ebusweni kubangela ukuthi ama-athomu asondele kakhulu kwezinye izindawo, ukuze amandla kagesi phakathi kwama-athomu akhe izibopho zamakhemikhali, njengokuhlangana phakathi kwezindawo ezimbili zento ehambayo. Lapho into ihamba, isibonelo uma ucindezela incwadi ebusweni betafula, ukunyakaza kwencwadi kuhlangabezana nezithiyo futhi ekugcineni kuyeke. Lokhu kungenxa yokwakheka nokukhululwa kwesibopho.
Uma ubuso bento bugudlana nobuso bento ethile, ngayinye yalezi zinto isebenza ekungqubuzaneni phakathi kwayo. Amandla okungqubuzana entweni ehambayo ahlala ephambene nokuqondisa kokunyakaza kwento. Ngaphezu kokuvimbela ukunyakaza kwezinto, ukungqubuzana kungabangela ukuguguleka nomonakalo. Singakubona lokhu enjinini yemoto. Isibonelo, lapho sinikeza injini yesithuthuthu uwoyela wokugcoba, empeleni sifuna ukunciphisa amandla okungqubuzana okwenzeka ngaphakathi enjinini. Uma inganikezwa uwoyela wokugcoba, injini yemoto yethu yonakala ngokushesha. Lesi sibonelo singenye yokulahlekelwa okubangelwa ukungqubuzana.
2. Izinhlobo ze amandla okungqubuzana
Kunezinhlobo ezimbili zamandla okungqubuzana, okungukuthi amandla okungqubuzana okungaguquki (fs) kanye namandla okungqubuzana kwe-kinetic (fk). Amandla okungqubuzana amile asebenza lapho into ingakahambi, kuyilapho amandla okungqubuzana amile asebenza lapho into ihamba. Uma ucindezela itafula, kodwa itafula lingakahambi, khona-ke amandla okungqubuzana asebenza etafuleni eliphumule ayimandla okungqubuzana amile. Ngokuphambene nalokho, lapho itafula lihamba, amandla okungqubuzana asebenza etafuleni yi-kinetic friction. Uma itafula elihambayo lingacindezelwa njalo, itafula lizoma ngemva kokuhamba isikhashana. Ithebula liyama ngenxa yamandla okungqubuzana amile avimba ukunyakaza kwetafula.
Wake washelela lapho unyathela into ebushelelezi? Uma ushelela, amandla okushelela asebenza phakathi kwesisekelo sesicathulo noma phansi kwesandali enobuso obubushelelezi yi-kinetic friction. Le nkinga ifana nalapho isithuthuthu noma imoto ihamba phezu kobuso bomgwaqo obumanzi nobubushelelezi, ibhuleka kuze kube yilapho isondo lishelela. Lapho amasondo eshelela, amandla okushelela asebenza ebusweni besondo kanye nobuso bomgwaqo yi-kinetic friction force. Ngokuphambene nalokho, uma uhamba, amandla okushelela asebenza phakathi kwesisekelo sezicathulo noma phansi kwezimbadada ezinobuso bomhlaba ayi-static friction force. Ngokufanayo, lapho amasondo engasheleli, amandla okushelela asebenza ebusweni besondo kanye nomgwaqo ayi-static friction.
2.1 Amandla okungqubuzana aqinile
Amandla okungqubuzana angaguquki amandla okungqubuzana asebenza ebusweni bezinto ezithintana lapho izinto zingakahambi.
Isithombe 1 sibonisa into esesebusweni bendiza eyisicaba. Uma into ingakahambi, khona-ke amandla okungqubuzana angaguquki (fs) mancane kunamandla okudonsa (F). Uma iqhubeka nokudonswa, khona-ke into izohamba. Lapho into efanele izohamba, ubukhulu bamandla okungqubuzana angaguquki (f)s) ilingana nobukhulu bamandla okudonsa (F).
UMthetho Wokuqala KaNewton uthi izinto ziwukuphumula uma amandla aphelele (amandla aphumelayo) engu-zero.
ΣFy = 0 (Ukuphumula kwento futhi ungahambi uye ohlangothini oluqondile)
N – w = 0
N = w (1.2)
Faka u-N esikhundleni se-equation 1.1 ku-equation 1.2 esikhundleni sika-N
fs = μs w
fs = μs mg (1.3)
fs = ukungqubuzana okungaguquki (N), μs = i-coefficient yokungqubuzana okungaguquki, N = amandla avamile (N), w = amandla adonsela phansi (N), m = isisindo (kg), g = ukusheshisa kwamandla adonsela phansi (m/s2)
Uma ufuna ukuthola i-coefficient yokungqubuzana okungaguquki, sebenzisa i-equation 1.1 b
Σfx = 0 (Into iyaphumula futhi ayihambi ngendlela evundlile)
F – fs = 0
F = fs (1.4)
Uma into iqala ukuhamba, amandla amakhulu okungqubuzana angaguquki alingana nobukhulu bamandla okusunduza noma okudonsa.
2.2 Amandla okungqubuzana kwe-Kinetic
Amandla okungqubuzana kwe-kinetic amandla okungqubuzana asebenza ebusweni bezinto ezithintana lapho into ihamba.
Uma ufuna ukuthola i-coefficient ye-kinetic friction (μ)k), sebenzisa isibalo esingu-1.5 b
Isithombe 2 sibonisa into edonswa njalo ukuze into ihambe ngesivinini esingaguquki. Uma ihamba ngesivinini esingaguquki, ubukhulu bamandla okungqubuzana kwe-kinetic (fk) bulingana nobukhulu bamandla okudonsa (F).
UMthetho Wokuqala KaNewton uthi into ihamba ngesivinini esingaguquki uma amandla aphelele (amandla aphumelayo) engu-zero.
ΣFx = 0 (izinto zihamba ngesivinini esingaguquki ohlangothini oluvundlile)
F – fk = 0
F = fk (1.6)
Inkinga yesampula 1:
Umfundi udonsa ugongolo olunesisindo esingu-1 kg olutholakala phezu kwetafula esebenzisa i-dynamometer (idivayisi yokulinganisa amandla). Uma ugongolo luzohamba, i-dynamometer ikhombisa inombolo engu-2 N. Uma ukusheshisa kwamandla adonsela phansi = 10 m/s2, nquma (a) ubukhulu bamandla okungqubuzana okungaguquki (b) i-coefficient yokungqubuzana okungaguquki
Isixazululo:
Kuyaziwa: m = 1 kg, F = 2 N, g = 10 m/s2, w = mg = 10 N
(a) fs
Uma umsebe uzohamba, ubukhulu bamandla okungqubuzana angaguquki = ubukhulu bamandla okudonsa (qhathanisa isibalo 1.4). Ngakho-ke, fs = F = 2 N.
(b) μs
fs = μs w
2 N = (μs)(10 N)
μs = 2 N / 10 N = 0.2
Inkinga yesampula 2:
Umshayo onesisindo esingu-1 kg otholakala ngaphezu kobuso betafula udonswa njalo ukuze umshayo uhambe ngesivinini esingaguquki. Uma umshayo uhamba ngesivinini esingaguquki, i-dynamometer ikhombisa inombolo 1 N. Uma ukusheshisa kwamandla adonsela phansi = 10 m/s2, nquma (a) ubukhulu bamandla okungqubuzana kwe-kinetic (b) i-coefficient yokungqubuzana kwe-kinetic
Isixazululo:
Kwaziwa: m = 1 kg, g = 10 m/s2, F = 1 N, w = mg = 10 N
(a) fk
Uma umsebe uhamba njalo noma uhamba ngesivinini esingaguquki, ubukhulu bamandla okungqubuzana kwe-kinetic = ubukhulu bamandla okudonsa (qhathanisa isibalo 1.6).
Ngakho-ke fk = F = 1 N
(b) μk
fk = μk w
1 N = (μk)(10 N)
μk = 1 N / 10 N = 0.1
