Mphamvu ya Conservative ndi mphamvu yosakhala ya Conservative
1. Gulu la Conservative
1.1 Kulemera (w)
Yang'anani chinthu chomwe chimakwera molunjika mpaka kufika pa msinkhu wapamwamba musanasunthe pansi kupita kumalo ake oyamba. Mukasuntha molunjika mmwamba ndi h, kulemera kumakhala kosiyana ndi kusuntha. Chifukwa chake, kulemerako kumagwira ntchito yotsutsa pa chinthucho.
W = wh (cos 180 o ) = – wh = – mgh
Chikafika kutalika kwakukulu, chinthucho chimatsika pansi kupita ku malo ake oyamba ndi h. Chikatsika pansi, kulemera kumakhala kofanana ndi kusamuka. Chifukwa chakuti chili m'njira yomweyo ndi kusamuka, kulemerako kumagwira ntchito bwino.
W = wh (cos 0 o ) = wh = mgh
Kulemera kwa chinthu (m), mphamvu yokoka (g), ndi kutalika (h) ndi chimodzimodzi, kotero ntchitoyo imachitika ndi kulemera kwake popeza chinthucho chimayamba kuyenda molunjika mmwamba mpaka chibwerere pamalo ake oyamba ndi zero.
W = mgh – mgh = 0
1.2 Mphamvu ya Masika
Yang'anani kasupe woikidwa pamalo opingasa. Ngati mbali yakumanja ya kasupe ikankhidwira kapena kukanikiza kumanzere, kasupeyo imakhala ndi mphamvu yokankhira kumanja. Mutha kutsimikizira izi mwa kukanikiza kasupe. Mwachitsanzo, ikani chinthu kumapeto kwa kumanja, kenako kanikizani chinthucho kumanzere. Kasupeyo akatembenuka ndi Δx, chotsani dzanja lanu pa chinthucho ndi kasupeyo. Dzanja likasakhudzananso ndi kasupeyo, kasupeyo adzakankhira chinthucho kumanja.
Chinthucho chikasuntha kumanzere, njira yoyendera ndi kusuntha kwake zimakhala zosiyana ndi njira ya mphamvu ya kasupe. Chifukwa chakuti njirazo zimakhala zosiyana, mphamvu ya kasupe imagwira ntchito yotsutsa.
W = – ½ k (Δx) 2
Chinthucho chikasuntha kupita kumanja, komwe chimayenda komanso komwe chikuyenda kumakhala kofanana ndi mphamvu ya kasupe. Chifukwa chakuti njira zake ndi zofanana, mphamvu ya kasupe imagwira ntchito yabwino.
W = ½ k (Δx) 2
Kasupe wogwiritsidwa ntchito ndi yemweyo, kotero chosasintha cha kasupe (k) ndi chomwecho. Kupatuka kwa kasupe (Δx) nakonso ndi komweko.
Motero, ntchitoyo imachitika potengera kulemera pamene chinthucho chikuyamba kusuntha kumanzere ndi Δx kenako nkubwerera kumanja ndi Δx ndi zero.
W = ½ k (Δx) 2 – ½ k (Δx) 2 = 0
Ntchitoyi imachitidwa ndi kulemera ndi mphamvu ya masika popeza chinthucho chimayamba kusuntha kuchokera pamalo ake oyamba mpaka chibwerere, ndiye kuti chili ndi zero. Ngati ntchitoyo idachitika ndi mphamvu popeza isuntha kuchokera pamalo ake oyamba mpaka chibwerere, ndiye kuti chili ndi zero, mphamvuyo imatchedwa mphamvu yosunga. Motero, mphamvu ya masika ndi kulemera ndi zitsanzo za mphamvu zosunga.
2. Mphamvu Yosakhala Yosunga Chikhalidwe
Yang'anani chinthu chomwe chikukankhidwira kumanja kenako nkuchikankhira kumbuyo kumanzere. Chinthucho chikasuntha kapena kusuntha kupita kumanja, njira yosunthira chinthucho imakhala yofanana ndi njira ya mphamvu yosonkhezera (F) ndipo imasiyana ndi njira ya mphamvu yokangana (f k ). Popeza chili mbali imodzi ndi njira yosinthira, mphamvu yosonkhezera imagwira ntchito yabwino pa chinthucho.
W = F s
M'malo mwake, mphamvu ya kinetic frictional imagwira ntchito yoyipa pa chinthucho.
W = – f k s
Ntchitoyi idachitika ndi mphamvu yokankhira ndi mphamvu yokangana pa chinthucho pamene chinthucho chikuyamba kusuntha kuchokera pamalo ake oyamba mpaka chibwererenso:
W = 2 F s
W = -2 f k s
Ntchitoyi imachitidwa ndi mphamvu yosonkhezera ndi mphamvu yosonkhezera chifukwa chinthucho chimayamba kusuntha kuchokera pamalo ake oyamba mpaka chibwerere, palibe chofanana ndi zero. Ngati ntchito yochitidwa ndi mphamvu kuyambira chinthucho chikuyamba kusuntha kuchokera pamalo ake oyamba mpaka chibwerere, palibe chofanana ndi zero, mphamvuyo imatchedwa mphamvu yosasinthika. Motero, mphamvu yosonkhezera ndi mphamvu yosonkhezera ndi zitsanzo za mphamvu zosasinthika.
1. Kodi mphamvu yosunga zinthu mwadongosolo ndi chiyani? Mphamvu yosunga zinthu mwadongosolo ndi imene ntchito yosuntha chinthu pakati pa mfundo ziwiri siimasiyana ndi njira yomwe yatengedwa. Mphamvu yokoka ndi yamagetsi ndi zitsanzo za mphamvu zosunga zinthu mwadongosolo.
2. Kodi ntchito yochitidwa ndi mphamvu yosunga zinthu imagwirizana bwanji ndi mphamvu yosunga zinthu? Ntchito yochitidwa ndi mphamvu yosunga zinthu pa chinthu chomwe chikuyenda kuchokera pa mfundo A kupita pa mfundo B ndi yofanana ndi kusintha kwa mphamvu yosunga zinthu (∆U) pakati pa mfundo ziwirizi: Izi zikutanthauza kuti ngati chinthu chikupeza mphamvu yosunga zinthu, ntchito yochitidwa ndi mphamvu yosunga zinthu imakhala yoyipa, ndipo mosemphanitsa.
3. Kodi mphamvu yosasunga zinthu mwachisawawa ndi chiyani? Mphamvu yosasunga zinthu mwachisawawa ndi imene ntchito yogwira posuntha chinthu pakati pa mfundo ziwiri imadalira njira yomwe yatengedwa. Kukangana ndi kukana mpweya ndi zitsanzo za mphamvu zosasunga zinthu mwachisawawa.
4. Kodi mphamvu yosasunga zinthu imakhudza bwanji mphamvu ya makina ya dongosolo? Mphamvu yosasunga zinthu imatha kusintha mphamvu yonse ya makina (chiwerengero cha mphamvu ya kinetic ndi potential) ya dongosolo. Izi zili choncho chifukwa ntchito yochitidwa ndi mphamvu yosasunga zinthu siisungidwa ngati mphamvu yothekera koma nthawi zambiri imasinthidwa kukhala mitundu ina ya mphamvu, monga kutentha.
5. Kodi munthu angadziwe bwanji ngati mphamvu ndi yosunga zinthu mwadongosolo kapena yosasunga zinthu mwadongosolo pogwiritsa ntchito njira yotseka? Kwa mphamvu yosunga zinthu mwadongosolo, ntchito ya ukonde yomwe yachitika pa chinthu ikadutsa njira yonse yotseka zinthu mwadongosolo ndi zero. Ngati ntchito ya ukonde yomwe yachitika pa njira yotseka zinthu mwadongosolo si zero, mphamvuyo si yosunga zinthu mwadongosolo.
6. Kodi kupindika kwa mphamvu kumagwira ntchito yotani podziwa ngati mphamvu ndi yosunga nthawi? Ngati kupindika kwa mphamvu ndi zero kulikonse mumlengalenga, mphamvuyo ndi yosunga nthawi. Ngati kupindika si zero, ndiye kuti mphamvuyo si yosunga nthawi.
7. Kodi mphamvu yokoka imakhudzana bwanji ndi mphamvu zosungira zinthu? Mphamvu yokoka imayamba chifukwa cha mphamvu yokoka yomwe imagwira ntchito mosasintha. Kukwera kwa kutalika kwa mphamvu yokoka kumabweretsa kuwonjezeka kwa mphamvu yokoka, pomwe ntchito yochitidwa ndi mphamvu yokoka ndi yoipa, zomwe zikutanthauza kuchepa kwa mphamvu yomwe imagwira ntchito pamene chinthu chikuyandikira Dziko Lapansi.
8. N’chifukwa chiyani kukangana sikuli ndi mphamvu yogwirizana nayo monga mphamvu zina zosungira zinthu? Kukangana ndi mphamvu yosasunga zinthu; chifukwa chake, ntchito yochitidwa ndi kukangana sisungidwa ngati mphamvu yosungira zinthu. M’malo mwake, nthawi zambiri imasinthidwa kukhala mitundu ina, monga kutentha, ndipo singathe kubwezeretsedwanso kwathunthu ngati mphamvu yamakina.
9. Mu chochitika chomwe chinthu chimatsika pansi pa mtunda wopendekeka, kodi mphamvu zosungira ndi zosasunga zimagwira ntchito bwanji? Chinthu chikamatsika pansi pa mtunda wopendekeka, mphamvu yokoka, mphamvu yosunga, imagwira ntchito pa chinthucho, ndikusintha mphamvu yake kukhala mphamvu ya kinetic. Ngati pali kukangana pakati pa chinthucho ndi mtunda wopendekeka (mphamvu yosasunga), imatsutsana ndi mayendedwe ndikuchepetsa mphamvu ya kinetic ya chinthucho, ndikusandutsa china kukhala kutentha.
10. Kodi mphamvu yonse ya dongosolo ingasungidwe ngakhale mphamvu zosasunga chilengedwe zikukhudzidwa? Inde, mphamvu yonse ya dongosolo (kuphatikizapo mitundu yonse ya mphamvu monga makina, kutentha, ndi zina zotero) imasungidwabe motsatira lamulo losunga mphamvu. Komabe, mphamvu zosasunga chilengedwe zikagwira ntchito, mphamvu ya makina (chiwerengero cha mphamvu za kinetic ndi potential) sizingasungidwe chifukwa zina mwa izo zimasinthidwa kukhala mitundu ina ya mphamvu, monga kutentha kapena phokoso.
