Kusunga mphamvu ya makina pamalo okhota - mavuto ndi mayankho
1. Ngati liwiro la mpira pa mfundo A ndi 6 m/s, liwiro la mpira pa mfundo B ndi √92 m/s, ndipo kuthamanga chifukwa cha mphamvu yokoka ndi g = 10 m/s 2. Kodi kutalika kwa mfundo B (h) ndi kotani?
Zodziwika:
Liwiro la mpira pa mfundo A (v)A) = 6 m/s
Liwiro la mpira pa mfundo B (v B ) = √92 m/s
Kuthamanga chifukwa cha mphamvu yokoka (g) = 10 m/s 2
Kutalika kwa A (h A ) = mamita 5.6
Kutalika kwa B (h B ) = h
Kufunidwa: Kutalika kwa mfundo B (h)
Yankho:
Mphamvu yoyambirira ya makina = mphamvu yokoka
Pa mfundo A, liwiro la mpira = 0, kotero mphamvu ya kinetic ya mpira = 0. KE = 1/2 mv 2 = 1/2 m (0) = 0.
Mpira uli pamtunda wa mamita 5.6 kotero mpira uli ndi mphamvu yokoka. Mphamvu yokoka : PE = mgh = m (10)(5.6) = 56 m
Mphamvu yoyambirira ya makina = mphamvu yokoka + mphamvu ya kinetic = 56 m + 0 = 56 m
Mphamvu yomaliza yamakina = mphamvu yokoka + mphamvu ya kinetic
Pa mfundo B, kutalika kwa mpira ndi h. Mphamvu yokoka: PE = mgh = m (10) h = 10 mh
Mphamvu ya kinetic ya mpira: KE = 1/2 mv 2 = 1/2 m (√92) 2 = 1/2 m (92) = 46 m
Mphamvu yomaliza ya makina = mphamvu yokoka + mphamvu ya kinetic = 10 mh + 46 m = m (10 h + 46)
Mfundo yosungira mphamvu zamakanika:
Mphamvu yoyambirira yamakina = mphamvu yomaliza yamakina
56 m = m (maola 10 + 46)
56 = maola 10 + 46
56 – 46 = maola 10
10 = maola 10
h = 10/10
h = mamita 1
2.
Ngati liwiro loyambirira = 0, kuthamanga chifukwa cha mphamvu yokoka = 10 m/s 2 , ndiye kuti liwiro lotani pa kutalika kwa B?
Zodziwika:
Liwiro loyambirira (v o ) = 0
Kutalika koyambirira (h o ) = 50 m – 10 m = 40 m
Kutalika komaliza (h t ) = 0
Kuthamanga chifukwa cha mphamvu yokoka (g) = 10 ms -2
Kufunidwa: Liwiro lomaliza (v t )
Yankho:
Kusintha kwa mphamvu ya kinetic:
ΔKE = 1/2 m (v t 2 – v o 2 ) = 1/2 m (v t 2 – 0) = 1/2 mv t 2
Kusintha kwa mphamvu zomwe zingatheke:
ΔPE = mg (h t – ho ) = m (10)(0-40) = m (10)(-40) = – 400 m
Werengerani liwiro lomaliza (v t ) pogwiritsa ntchito equation ya mfundo yosungira mphamvu zamakanika :
0 = ΔKE + ΔPE
0 = 1/2 mv t 2 - 400 m
1/2 mv t 2 = 400 m
1/2 v t 2 = 400
v t 2 = 2 (400)
v t = √(400)(2)
v t = 20√2 m/s
- Kodi tanthauzo la "kusunga mphamvu zamakanika" ndi chiyani?
- Yankho: Kusunga mphamvu ya makina kumatanthauza kuti mphamvu yonse ya makina (chiwerengero cha mphamvu ya kinetic ndi potential) ya dongosolo lokhalokha imakhalabe yokhazikika ngati mphamvu zosungira, monga mphamvu yokoka, ndizo zikugwira ntchito pa izo.
- Kodi chinthu choyenda pamalo opindika (monga mpira wogubuduzika pansi pa mpanda wopindika) chimasunga bwanji mphamvu zake zamakanika?
- Yankho: Pamene chinthucho chikuyenda pansi pa malo opindika, mphamvu zomwe zingatheke zimasanduka mphamvu ya kinetic, koma mphamvu yonse ya makina imakhalabe yokhazikika, poganiza kuti palibe mphamvu zosasintha (monga kukangana) zomwe zikugwira ntchito.
- Ngati mpira watulutsidwa kuchokera pamalo opumulira pamwamba pa ramp yokhota, kodi mphamvu yake ya kinetic imasintha bwanji pamene ikuyenda pansi pa ramp?
- Yankho: Mphamvu ya kinetic ya mpira imawonjezeka pamene ukutsika pansi pa ramp chifukwa mphamvu yake yomwe ingathe kuchepa imachepa ndipo imasanduka mphamvu ya kinetic.
- Ngati palibe kukangana, kodi liwiro la mpira pansi pa slide yokhota lingafanane bwanji ndi slide yolunjika ya kutalika komweko?
- Yankho: Liwiro la mpira pansi lingakhale lofanana pa ma slide opindika komanso owongoka chifukwa kusintha kwa mphamvu zomwe zingatheke kukhala mphamvu ya kinetic kumadalira kutalika koyima, osati njira yomwe yatengedwa.
- N’chifukwa chiyani mpira sungafike kutalika kwake koyambirira ukakulungidwa pa malo otsetsereka atatsika kuchokera kutalika kwinakwake?
- Yankho: Ngati pali mphamvu zosasintha monga kukangana komwe kumagwira ntchito pa mpira, zimagwira ntchito motsutsana ndi kayendedwe kake, kusintha mphamvu zina za makina a mpira kukhala mitundu ina, monga kutentha. Zotsatira zake, mpirawo ungakhale wopanda mphamvu zokwanira kuti ufike kutalika kwake koyambirira.
- Ngati zinthu ziwiri zosiyana (monga mpira ndi kyubiki) zikuyenda pansi pa ramp yokhotakhota kuchokera kutalika komweko popanda kugubuduzika, kodi zidzakhala ndi liwiro lomwelo pansi? Chifukwa chiyani?
- Yankho: Inde, adzakhala ndi liwiro lomwelo pansi. Poganiza kuti palibe kugubuduzika kapena kukangana, chinthu chokhacho chomwe chimatsimikizira liwiro lawo ndi kusunga mphamvu kutengera kutalika koyambirira, osati mawonekedwe awo.
- Kodi kupindika kwa pamwamba kumakhudza bwanji mphamvu yachibadwa ya chinthu chomwe chikuyenda pambali pake?
- Yankho: Kupindika kumeneku kumapangitsa kuti mphamvu yachibadwa isinthe pamene chinthucho chikuyenda. Pamwamba pa khola lopindika (monga mkati mwa mbale), mphamvu yachibadwa imakhala yayikulu pansi chifukwa cha mphamvu yapakati yomwe imafunika kuti munthu ayende mozungulira. Mosiyana ndi zimenezi, pamwamba pa khola lopindika, mphamvu yachibadwa imatha kuchepa kapena kukhala zero (chinthu chimachoka pamwamba) pamwamba kwambiri.
- Kodi gawo la kupindika kwa radius limagwira ntchito yotani pakusunga mphamvu zamakanika pamalo opindika?
- Yankho: Kupindika kwa mpweya kokha sikukhudza mwachindunji kusungidwa kwa mphamvu zamakanika. Komabe, kumatha kukhudza mphamvu yachibadwa ndipo, ngati pali kukangana, kuchuluka kwa mphamvu zomwe zimatayika ku mphamvu zosasinthika.
- Ngati njanji ili ndi kutsika pakati (monga momwe imakhota ngati U), kodi mphamvu ya makina ya chinthu imasiyana bwanji pamene ikuyenda kudzera mu kutsika ndikukwera mbali inayo?
- Yankho: Mphamvu ya chinthucho idzachepa ikalowa m'madzi ndikuwonjezera mphamvu yake ya kinetic. Pamene ikukwera mbali inayo, mphamvu yake ya kinetic idzachepa, ndipo mphamvu yake idzawonjezeka. Ngati mphamvu zosungira zokha zigwira ntchito, mphamvu yonse ya makina imakhalabe yokhazikika panthawi yonse yoyenda.
- Kodi chinthu chingakhale ndi mphamvu ya kinetic yosinthika komanso yozungulira ikasuntha pamwamba pokhota?
- Yankho: Inde, ngati chinthu ngati mpira chikugubuduzika (popanda kutsetsereka) pamalo opindika, chidzakhala ndi mphamvu ya kinetic yosinthika chifukwa cha pakati pake poyenda ndi mphamvu ya kinetic yozungulira chifukwa cha kuzungulira kwake mozungulira mzere wake.
