Chitsanzo cha kugwiritsa ntchito malamulo a Newton pa malo otsetsereka (pali kukangana)

Zitsanzo ziwiri za kugwiritsa ntchito malamulo a Newton pa malo otsetsereka (pali kukangana)

1. Kulemera kwa chipikacho ndi 2 kg, kuthamanga chifukwa cha mphamvu yokoka = 10 m/s², coefficient ya static ndi kinetic friction ndi 0,2 ndi 0,1. Kodi block ili chikhalire kapena ikuyenda? Ngati block ikuyenda, dziwani (a) mphamvu yomwe imachokera yomwe imafulumizitsa block (b) kukula ndi komwe block ikuyenda!
Zokambirana
Ndizodziwika kuti :
Kulemera (m) = 2 kg
Kuthamanga chifukwa cha mphamvu yokoka (g) = 10 m/s²
Chokwanira cha kukangana kosasinthasintha = 0,2
Chokwanira cha kukangana kosasinthasintha = 0,1
Kulemera kwa chipika (w) = mg = (2)(10) = 20 Newton
w_x = w sin 30^o = (20)(0,5) = 10 Newtons
w_y = w cos 30^o = (20)(0,5√3) = 10√3 Ma Newton
Mphamvu yachibadwa (N) = w_y = 10√3 Newton
Mphamvu yosasunthika yokangana (f)_s) = (0,2)(10√3) = 2√3 Ma Newton
Mphamvu ya kukangana kwa kinetic (f)_k) = (0,1)(10√3) = √3 Newtons
Anafunsa Kodi chipikacho chili chikhalire kapena chikuyenda? Ngati chikuyenda, dziwani mphamvu yomwe imachokera yomwe imafulumizitsa chipikacho ndi kuthamanga kwa chipikacho!

Yankhani :
Chipikacho chili pamalo opumulira ngati w_x <f_s, chipikacho chimayenda ngati w_x > f_sChifukwa w_x = 10 Newton ndi f_s = 2√3 Newtons, kotero zatsimikiziridwa kuti chipikacho chimapita pansi.
(a) mphamvu yochokerapo yomwe imafulumizitsa chipikacho
Pamene chipikacho chikuyenda, mphamvu yokangana yomwe imagwira ntchito pa chipikacho ndi mphamvu yokangana ya kinetic (f)._k).
(b) kukula ndi njira ya kuthamanga kwa chipikacho
Kukula kwa kuthamanga kwa chipikacho ndi 4,15 m/s² ndipo komwe kuthamangira kwa block kuli pansi.

2. Kulemera kwa chipikacho ndi 4 kg, kuthamanga chifukwa cha mphamvu yokoka ndi 10 m/s². Ma coefficients a static ndi kinetic friction ndi 0,4 ndi 0,2. Ngati kukula kwa mphamvu F ndi 40 Newton, kodi block idakali kapena ikuyenda? Ngati block ikuyenda, dziwani (a) mphamvu yochokera yomwe imafulumizitsa block (b) kukula ndi komwe block ikuyenda!
Zokambirana
Ndizodziwika kuti :
Kulemera (m) = 4 kg
Kuthamanga chifukwa cha mphamvu yokoka (g) = 10 m/s²
Chokwanira cha kukangana kosasinthasintha = 0,4
Chokwanira cha kukangana kosasinthasintha = 0,2
Kulemera kwa chipika (w) = mg = (4)(10) = 40 Newton
w_x = w sin 30^o = (40)(0,5) = 20 Newtons
w_y = w cos 30^o = (40)(0,5√3) = 20√3 Ma Newton
Mphamvu yachibadwa (N) = w_y = 20√3 Newton
Mphamvu yosasunthika yokangana (f)_s) = (0,4)(20√3) = 8√3 Ma Newton
Mphamvu ya kukangana kwa kinetic (f)_k) = (0,2)(20√3) = 4√3 Ma Newton
F = 40 Newton
Anafunsa Kodi chipikacho chili chikhalire kapena chikuyenda? Ngati chikuyenda, dziwani mphamvu yomwe imachokera yomwe imafulumizitsa chipikacho ndi kuthamanga kwa chipikacho!
Yankhani :
Chipikacho chimapita pansi ngati F < w_x +f_s. Chipikacho chimapita mmwamba ngati F > w_x +f_s. F = 40 Newton, w_x = 20 Newton ndi f_s = 8√3 = 13,6 Newtons, kotero zatsimikiziridwa kuti chipikacho chimapita mmwamba chifukwa F ndi wamkulu kuposa w_x +f_s.
(a) mphamvu yochokerapo yomwe imafulumizitsa chipikacho
Pamene chipikacho chikuyenda, mphamvu yokangana yomwe imagwira ntchito pa chipikacho ndi mphamvu yokangana ya kinetic (f)._k).
(b) kukula ndi njira ya kuthamanga kwa chipikacho
Kukula kwa kuthamanga kwa chipikacho ndi 1,6 m/s² ndipo komwe kuthamangira kwa block kuli mmwamba.

[Chingerezi: Kuyenda pa ndege yokhotakhota ndi mphamvu yokangana]