Mohlala oa ho sebelisa melao ea Newton sebakeng se sekametseng ka thata (ho na le khohlano)

Mehlala e 'meli ea ho sebelisa melao ea Newton ho lifofane tse sekametseng ka thata (ho na le khohlano)

1. Boima ba boloko ke 2 kg, ho potlaka ka lebaka la matla a khoheli = 10 m/s², coefficient ea static le kinetic friction ke 0,2 le 0,1. Na block e ntse e le teng kapa e tsamaea? Haeba block e tsamaea, fumana (a) matla a hlahang a potlakisang block (b) boholo le tataiso ea lebelo la block!
Puisano
Hoa tsebahala :
Boima (m) = 2 kg
Ho potlaka ka lebaka la matla a khoheli (g) = 10 m/s²
Koefficient ea khohlano e sa fetoheng = 0,2
Koefficient ea khohlano e sa fetoheng = 0,1
Boima ba boloko (w) = mg = (2)(10) = 20 Newton
w_x = sebe sa 30^o = (20)(0,5) = 10 Newton
w_y = w cos 30^o = (20)(0,5√3) = 10√3 Li-Newton
Matla a tloaelehileng (N) = w_y = 10√3 Newton
Matla a khohlano a sa fetoheng (f)_s) = (0,2)(10√3) = 2√3 Li-Newton
Matla a khohlano ea kinetic (f)_k) = (0,1)(10√3) = √3 Li-Newton
E botsitsoe : Na boloko e ntse e le teng kapa e a tsamaya? Haeba e tsamaya, fumana matla a hlahang a potlakisang boloko le ho potlakisa ha boloko!

Jawab :
Boloko bo phomotse haeba w_x < f_s, boloko bo tsamaea haeba w_x > f_sHobane w_x = 10 Newton le f_s = 2√3 Newtons, kahoo ho fihlelletswe qeto ya hore boloko bo theohela tlase.
(a) matla a hlahang a potlakisang thibelo
Ha boloko bo tsamaya, matla a kgohlano a sebetsang hodima boloko ke matla a kgohlano a kinetic (f)._k).
(b) boholo le tataiso ea lebelo la boloko
Boholo ba lebelo la boloko ke 4,15 m/s² 'me tataiso ea ho potlaka ha boloko e theohela tlase.

2. Boima ba boloko ke 4 kg, lebelo le bakoang ke matla a khoheli ke 10 m/s². Li-coefficient tsa khohlano e sa fetoheng le ea kinetic ke 0,4 le 0,2. Haeba boholo ba matla F e le 40 Newton, na boloko bo ntse bo le teng kapa boa tsamaea? Haeba boloko bo tsamaea, fumana (a) matla a hlahang a potlakisang boloko (b) boholo le tataiso ea ho potlaka ha boloko!
Puisano
Hoa tsebahala :
Boima (m) = 4 kg
Ho potlaka ka lebaka la matla a khoheli (g) = 10 m/s²
Koefficient ea khohlano e sa fetoheng = 0,4
Koefficient ea khohlano e sa fetoheng = 0,2
Boima ba boloko (w) = mg = (4)(10) = 40 Newton
w_x = sebe sa 30^o = (40)(0,5) = 20 Newton
w_y = w cos 30^o = (40)(0,5√3) = 20√3 Li-Newton
Matla a tloaelehileng (N) = w_y = 20√3 Newton
Matla a khohlano a sa fetoheng (f)_s) = (0,4)(20√3) = 8√3 Li-Newton
Matla a khohlano ea kinetic (f)_k) = (0,2)(20√3) = 4√3 Li-Newton
F = 40 Newton
E botsitsoe : Na boloko e ntse e le teng kapa e a tsamaya? Haeba e tsamaya, fumana matla a hlahang a potlakisang boloko le ho potlakisa ha boloko!
Jawab :
Boloko bo theohela tlase haeba F < w_x +f_s. Boloko bo nyolohela hodimo haeba F > w_x +f_s. F = 40 Newton, w_x = 20 Newton le f_s = 8√3 = 13,6 Newtons, kahoo ho fihlelletswe qeto ya hore boloko bo nyolohela hodimo hobane F e kgolo ho feta w_x +f_s.
(a) matla a hlahang a potlakisang thibelo
Ha boloko bo tsamaya, matla a kgohlano a sebetsang hodima boloko ke matla a kgohlano a kinetic (f)._k).
(b) boholo le tataiso ea lebelo la boloko
Boholo ba lebelo la boloko ke 1,6 m/s² 'me tataiso ea ho potlaka ha boloko e ea holimo.

[Senyesemane: Motsamao sefofaneng se sekametseng ka thata ka matla a khohlano]