Izibonelo ezimbili zokusebenzisa imithetho kaNewton ohlelweni lomthwalo wezintambo kanye ne-pulley
1. Isisindo sebhulokhi 1 singama-2 kg, isisindo sebhulokhi 2 singama-3 kg, ukusheshisa okubangelwa amandla adonsela phansi kungu-10 m/s2. Nquma (a) ubukhulu kanye nesiqondiso sokusheshisa kwesistimu (b) ubukhulu bamandla okucindezela entanjeni!
Ingxoxo
I-Diketahui :
Isisindo sebhulokhi 1 (m1) = 2 kg
Isisindo sebhulokhi 2 (m2) = 3 kg
Ukusheshisa ngenxa yamandla adonsela phansi (g) = 10 m/s2
Isisindo sebhulokhi 1 (w)1) = m1 g = (2)(10) = 20 Newton
Isisindo sebhulokhi 2 (w)2) = m2 g = (3)(10) = 30 Newton
Jawab :
(a) ubukhulu kanye nesiqondiso sokusheshisa kwesistimu
w2 > w1 Ngakho-ke, ibhulokhi 2 liya phansi, ibhulokhi 1 liya phezulu. Ngakho uhlelo luhamba ngokwewashi. Amandla aqondene nokunyakaza kwesistimu angu-w2 kanye no-T1, kuyinto enhle. Amandla aphikisana nokunyakaza kwesistimu, okungukuthi u-T2 kanye no-w1, kuyinto engemihle.
Amandla okucindezela entanjeni afana kuzo zonke izingxenye zentambo.
Ngakho-ke u-T1 =T2 =T
w2 – T + T – w1 = (m1 +m2) futhi
w2 - w1 = (m1 +m2) futhi
30 – 20 = (2 + 3) a
10 = 5 a
a = 10/5
a = 2 m/s2
Ubukhulu bokusheshisa kwesistimu buyi-2 m/s2.
(b) ubukhulu bokucindezeleka entanjeni
Ibhulokhi lokubuyekeza 2.
Kunamandla amabili asebenza kubhlokhi 2. I-Pertama, isisindo sebhulokhi 2 (w2) eqondiswe phansi, ngendlela efanayo nokunyakaza kwebhulokhi 2, ngakho-ke inophawu oluhle. I-Kedua, amandla okucindezela entambo ebhulokini 2 (T2) eqondiswe phezulu, ngokuphambene nesiqondiso sokunyakaza kwebhulokhi 2, ngakho-ke inophawu olubi. Sebenzisa umthetho wesibili kaNewton:
Ibhulokhi lokubuyekeza 1.
Kunamandla amabili asebenza kubhlokhi 1. I-Pertama, isisindo sebhulokhi 1 (w1) eqondiswe phansi, ngokuphambene nesiqondiso sokunyakaza kwebhulokhi 1, ngakho-ke inophawu olubi. I-Kedua, amandla okucindezela entambo ebhulokini 1 (T1) eqondiswe phezulu, ngendlela efanayo nokunyakaza kwebhulokhi 1, ngakho-ke inophawu oluhle. Sebenzisa umthetho wesibili kaNewton:
Ubukhulu bamandla okucindezela intambo = T1 =T2 = T = 24 Newton
2. Ibhloko 1 lisendaweni elukhuni, eyisicaba enobuhixihixi. Isisindo sebhloko 1 singama-2 kg, isisindo sebhloko 2 singama-4 kg, kanti ukusheshisa ngenxa yamandla adonsela phansi kungu-10 m/s.2, i-coefficient ye-static kanye ne-kinetic friction ingu-0,4 kanye no-0,3. Ingabe uhlelo luphumule noma luyahamba? Uma uhlelo luhamba, thola ubukhulu kanye nesiqondiso sokusheshisa kohlelo!
Ingxoxo
Amandla okucindezela (T) entambo awaboniswa ngoba, njengasekubalweni kwangaphambilini, amandla okucindezela entambo ekugcineni asuswa ku-equation. Uma ibuzwa embuzweni, amandla okucindezela entambo kudingeka aboniswe, kodwa uma ingabuzwanga embuzweni, vele ungayinaki.
I-Diketahui :
Kubuziwe : Ingabe uhlelo lumile noma luyahamba? Uma luhamba, thola ubukhulu kanye nesiqondiso sokusheshisa kohlelo!
Jawab :
Ngoba w2 > fs (40 Newton > 8 Newton) bese uhlelo luhamba, lapho ibhloko 2 lihamba khona liqonde phansi bese ibhloko 1 lihamba ngokuvundlile liye kwesokudla. Uma uhlelo luhamba, amandla okungqubuzana asebenza kubhloko 1 yiwona amandla okungqubuzana kwe-kinetic (f).kSebenzisa umthetho wesibili kaNewton:
Ubukhulu bokusheshisa kwesistimu buyi-5,7 m/s2
[IsiNgisi: Imizimba exhunywe ngezintambo nama-pulley – ukusetshenziswa komthetho kaNewton wokunyakaza]
