Isihloko mayelana nokulingana komzimba oqinile
1. Isimo sokuqala
UMthetho Wesibili kaNewton uthi uma amandla avelayo entweni (into ebhekwa njengenhlayiya eyodwa) engekho u-zero,
khona-ke into izohamba ngokusheshisa okuqhubekayo, lapho isiqondiso sokunyakaza kwento = isiqondiso samandla aphelele. Uma amandla aphumelayo engu-zero, khona-ke into iphumule noma ihamba ngesivinini esingaguquki.
ΣF = ma
Uma into iphumule noma ihamba ngesivinini esingaguquki, into ayinayo i-acceleration (a). Ngenxa yokuthi i-acceleration (a) = 0, i-equation engenhla ishintsha ibe yi:
ΣF = 0
Lesi sibalo singahlukaniswa ngezingxenye zaso ku-x-axis, y-axis, kanye ne-z-axis.
ΣFx = 0 (1)
ΣFy = 0 (2)
ΣFz = 0 (3)
Uma amandla esebenza ngendlela evundlile, sisebenzisa i-equation 1. Uma amandla esebenza ngendlela evundlile kuphela, sisebenzisa i-equation 2. Uma amandla esebenza endizeni (izilinganiso ezimbili), sisebenzisa i-equation 1 kanye ne-equation 2. Ngokuphambene nalokho, uma amandla esebenza esikhaleni (izilinganiso ezintathu), sisebenzisa izilinganiso 1, 2, kanye no-3.
Amandla ayinani le-vector, amandla anobukhulu kanye nesiqondiso. Uma kubhekiselwa kuma-coordinates e-Cartesian (x, y, z) nangokuhambisana nesivumelwano,
uma amandla ebheke ohlangothini lwe-x-axis engemihle (ngakwesobunxele) noma ohlangothini lwe-y-axis engemihle (phansi), khona-ke amandla angemihle. Ngokuphambene nalokho, uma amandla ebheke ohlangothini lwe-x-axis engemihle (ngakwesokudla) noma ohlangothini lwe-y-axis engemihle (phezulu), khona-ke amandla angemihle.
Isibonelo 1.
F = Amandla okudonsa, fg = amandla okungqubuzana, N = amandla ajwayelekile, w = isisindo, m = isisindo, g = ukusheshisa kwamandla adonsela phansi. Into iphumule ngenxa yesamba samandla asebenza kuyo = 0.
Buyekeza amandla ngalinye asebenza entweni.
Amandla asebenza ohlangothini oluvundlile (x-axis):
ΣFx = 0
F – fg = 0
F = fg
Amandla okudonsa (F) kanye namandla okungqubuzana (f fr ) anobukhulu obufanayo, kodwa ohlangothini oluphambene. Isiqondiso samandla okudonsa ngakwesokudla noma ngase-x-axis enhle (inani elihle), esikhundleni sesiqondiso samandla okungqubuzana kwesobunxele noma ngase-x-axis engemihle (engemihle). Ngoba ubukhulu bamandla womabili buyafana (okuboniswa ubude bomcibisholo) futhi isiqondiso siphambene, ubukhulu bala mandla amabili bungu-0.
Amandla asebenza engxenyeni eqondile (i-y-axis):
ΣF y = 0
N – w = 0
N – mg = 0
N = mg
Engxenyeni eqondile (y-axis), kunesisindo (w) kanye namandla ajwayelekile (N). Isiqondiso sesisindo siqonde ngqo enkabeni yomhlaba noma sibheke ku-y-axis engemihle (inani elingemihle), kuyilapho isiqondiso samandla avamile abheke ku-y-axis singemihle (inani elihle). Ubukhulu bala mandla amabili buyafana, kodwa isiqondiso siphambene, ngakho la mandla amabili ayaqedana.
Into esesibonelweni esingenhla iphumule ngoba amandla aphelele noma isamba sawo wonke amandla asebenza entweni, kokubili ku-axis evundlile kanye ne-axis eqondile, = 0.
Isibonelo 2.
Isisindo kanye namandla avamile asebenza kule nto akudonswa ngoba womabili amandla ayaqedana. Kuzo zombili izinhlangothi zento kusetshenziswa amandla u-F njengoba kubonisiwe. Womabili la mandla anobukhulu obufanayo, kodwa aphambene. Ingabe izinto zizophumula?
Ukuze sikusize uqonde lokhu, beka incwadi etafuleni. Ekuqaleni, incwadi yayiphumule ngoba amandla asebenzayo encwadini ayengu-zero.
Okulandelayo, nikeza amandla kuzo zombili izinhlangothi zencwadi, njengoba kuboniswe esithombeni. Uma wenza amandla kuzo zombili izinhlangothi zencwadi, kufana nokuthi ujikeleza incwadi. Yiqiniso, incwadi iyajikeleza. Incwadi iyajikeleza ngenxa yomzuzu wamandla okhiqizwa amandla F. I-axis yokujikeleza itholakala phakathi nencwadi. Uma sicabanga ukuthi akukho mandla okungqubuzana asebenza entweni, umzuzu wamandla ophumelayo yinombolo yomzuzu wamandla okhiqizwa amandla amabili F.
Indlela yokujikeleza kwento iqondiswa ngokwewashi ukuze izikhathi ezimbili zamandla zibe zimbi (hhayi ukuqedana).
2. Isimo sesibili
Ngokusekelwe esibonelweni sesi-2 esingenhla, kungaphethwa ngokuthi uma umzuzu wamandla ophumela entweni ungewona u-zero (into ibhekwa njengento eqinile), khona-ke into izojikeleza.
Στ = I α
Ukuze izinto zingajikelezi, umzuzu wamandla ophumelayo kumele ube yi-zero. Uma into imile (ingajikelezi), into ayinayo i-angular acceleration. Ngenxa ye-angular acceleration = 0, i-equation engenhla ishintshela ku:
Στ = 0
