Izibonelo ezimbili zokusebenzisa imithetho kaNewton ezindizeni ezithambekele kabi (kukhona ukungqubuzana)
1. Isisindo sebhulokhi singama-2 kg, ukusheshisa ngenxa yamandla adonsela phansi = 10 m/s2, i-coefficient ye-static kanye ne-kinetic friction ingu-0,2 kanye no-0,1. Ingabe ibhloko isamile noma iyahamba? Uma ibhloko ihamba, nquma (a) amandla aphumela ekusheshiseni ibhloko (b) ubukhulu kanye nesiqondiso sokusheshisa kwebhloko!
Ingxoxo
I-Diketahui :
IMisa (m) = 2 kg
Ukusheshisa ngenxa yamandla adonsela phansi (g) = 10 m/s2
I-coefficient yokungqubuzana okuqinile = 0,2
I-coefficient yokungqubuzana okuqinile = 0,1
Isisindo sebhulokhi (w) = mg = (2)(10) = 20 Newton
wx = isono 30o = (20)(0,5) = 10 Newton
wy = w cos 30o = (20)(0,5√3) = 10√3 AmaNewton
Amandla ajwayelekile (N) = wy = 10√3 uNewton
Amandla okungqubuzana aqinile (f)s) = (0,2)(10√3) = 2√3 AmaNewton
Amandla okungqubuzana kwe-kinetic (f)k) = (0,1)(10√3) = √3 AmaNewton
Kubuziwe : Ingabe ibhlokhi isamile noma iyahamba? Uma ihamba, thola amandla aphumayo asheshisa ibhlokhi kanye nokusheshisa kwebhlokhi!
Jawab :
Ibhloko liphumule uma wx < fs, ibhulokhi lihamba uma u-wx > fsNgoba wx = 10 uNewton no-fs = 2√3 AmaNewton, ngakho-ke kuphethwa ngokuthi ibhloko liyehla liye phansi.
(a) amandla aphumela ekusheshiseni ibhulokhi
Uma ibhloko lihamba, amandla okungqubuzana asebenza kubhloko yiwona amandla okungqubuzana e-kinetic (f).k).
(b) ubukhulu kanye nesiqondiso sokusheshisa kwebhulokhi
Ubukhulu bokusheshisa kwebhulokhi buyi-4,15 m/s2 futhi isiqondiso sokusheshisa kwebhulokhi siphansi.
2. Isisindo sebhulokhi singama-4 kg, ukusheshisa ngenxa yamandla adonsela phansi kungu-10 m/s2. Ama-coefficients okungqubuzana okungaguquki kanye nokujiya kwe-kinetic angama-0,4 kanye no-0,2. Uma ubukhulu bamandla u-F bungu-40 Newton, ingabe ibhloko limile noma liyahamba? Uma ibhloko lihamba, nquma (a) amandla aphumela ekusheshiseni ibhloko (b) ubukhulu kanye nesiqondiso sokusheshisa kwebhloko!
Ingxoxo
I-Diketahui :
IMisa (m) = 4 kg
Ukusheshisa ngenxa yamandla adonsela phansi (g) = 10 m/s2
I-coefficient yokungqubuzana okuqinile = 0,4
I-coefficient yokungqubuzana okuqinile = 0,2
Isisindo sebhulokhi (w) = mg = (4)(10) = 40 Newton
wx = isono 30o = (40)(0,5) = 20 Newton
wy = w cos 30o = (40)(0,5√3) = 20√3 AmaNewton
Amandla ajwayelekile (N) = wy = 20√3 uNewton
Amandla okungqubuzana aqinile (f)s) = (0,4)(20√3) = 8√3 AmaNewton
Amandla okungqubuzana kwe-kinetic (f)k) = (0,2)(20√3) = 4√3 AmaNewton
F = 40 Newton
Kubuziwe : Ingabe ibhlokhi isamile noma iyahamba? Uma ihamba, thola amandla aphumayo asheshisa ibhlokhi kanye nokusheshisa kwebhlokhi!
Jawab :
Ibhulokhi ihlela phansi uma u-F < wx +fsIbhulokhi iqhubekela phezulu uma u-F > wx +fs. F = 40 Newton, wx = 20 uNewton no-fs = 8√3 = 13,6 AmaNewton, ngakho-ke kuphethwa ngokuthi ibhloko liya phezulu ngoba u-F mkhulu kuno-wx +fs.
(a) amandla aphumela ekusheshiseni ibhulokhi
Uma ibhloko lihamba, amandla okungqubuzana asebenza kubhloko yiwona amandla okungqubuzana e-kinetic (f).k).
(b) ubukhulu kanye nesiqondiso sokusheshisa kwebhulokhi
Ubukhulu bokusheshisa kwebhulokhi buyi-1,6 m/s2 futhi isiqondiso sokusheshisa kwebhulokhi siphezulu.
[IsiNgisi: Ukunyakaza endizeni ethambekele emangelengele ngamandla okungqubuzana]
