Chitsanzo cha mafunso okhudza mphamvu yokangana

Zitsanzo 6 za Mafunso Okhudza Mphamvu Yotsutsana

1. Chipika cholemera makilogalamu 1 chimakhala pamalo osalala. Chiŵerengero cha kukangana kosasinthasintha ndi 0,4 ndipo kuthamanga chifukwa cha mphamvu yokoka ndi 10 m/s.²Dziwani (a) kukula kwa mphamvu yosasunthika (b) mphamvu yocheperako yokakamiza F kuti chipikacho chiyambe kuyenda!
Zokambirana
Ndizodziwika kuti :
Anafunsa :
(a) Kukula kwa mphamvu yosasunthika (b) Kukula kwa mphamvu yocheperako yokakamiza (F)
Yankhani :
(a) Kukula kwa mphamvu yokangana yosasinthasintha (f)_s)
(b) Mphamvu yochepa yokakamiza (F)
Ngati chinthu chakokedwa ndi mphamvu F koma chinthucho chili pamalo opumulira, ndiye kuti static friction ikugwira ntchito pa chinthucho. Ngati chinthucho chakokedwa ndi mphamvu F ndipo chinthucho chikuyenda kale, ndiye kuti kinetic friction ikugwira ntchito pa chinthucho. Static friction imaletsa kuyenda kwa chinthucho ndipo monga momwe zasonyezedwera pachithunzichi, njira ya static friction imatsutsana ndi njira ya tensile force (F). Pamene tensile force (F) ili ndi kukula kofanana ndi static friction force, ndiye kuti chinthucho chimasuntha (chinthucho chimakhalabe pamalo opumulira). Chinthucho chimayamba kuyenda pamene tensile force ndi yayikulu kuposa static friction force.
Kotero mphamvu yocheperako yogwira (F) kuti chipikacho chiyambe kuyenda ndi ma Newton anayi.

2. Chipika cholemera makilogalamu 1 chomwe chimayikidwa pamalo osalala osalala chimakokedwa ndi mphamvu F mwanjira yoti chipipikacho chiziyenda molunjika pa liwiro losasintha. Ngati coefficient of kinetic friction ndi 0,1, dziwani kukula kwa mphamvu yokoka F! (g = 10 m/s)²)  
Zokambirana
Ndizodziwika kuti :
Anafunsa : F
Yankhani :
Chipika choyenda molunjika pa liwiro losasintha = chipika choyenda pa liwiro losasintha = chipika choyenda popanda kufulumizitsa. Lamulo Loyamba la Newton limati ngati mphamvu yochokerapo ikugwira ntchito pa chinthu = 0 ndiye kuti chinthucho chili pamalo opumulira kapena chikuyenda pa liwiro losasintha.
Chipikacho chimayenda pa liwiro losasintha, motero mphamvu yochokera pa chipikacho = 0. Kuti mphamvu yochokerapo ifike = 0, kuwonjezera pa mphamvu yokoka F kumanja, payenera kukhala mphamvu yomwe ili ndi kukula kofanana ndi F koma yolunjika kumanzere. Mphamvu yomwe ikukambidwa ndi mphamvu yokangana, mphamvu yokangana ya kinetic yomwe imagwira ntchito pa chipikacho pamene chinthucho chikuyenda. Mwa masamu:
Popeza chinthucho chimayenda molunjika pa liwiro losasintha, kukula kwa mphamvu yokoka F = f_s = 1 Newton

3. Bokosi lolemera makilogalamu 1 likutsetsereka pansi pa liwiro losasintha pa malo otsetsereka. Dziwani kuchuluka kwa kugwedezeka kwa kinetic… (g = 10 m/s)²)
Zokambirana

Mawu ofotokozera:
w = mphamvu yokoka, w_x = gawo la mphamvu yokoka lofanana ndi pamwamba pa ndege yopendekeka, w_y = gawo la mphamvu yokoka yolunjika ku ndege yopendekera, N = mphamvu yachibadwa, f_k = mphamvu ya kukangana kwa kinetic.

Yankhani :
Bokosilo limatsika pansi pa liwiro losasintha, motero mphamvu yochokerapo = 0. Bokosilo limayenda pamwamba pa ndege yopendekeka, pomwe pamwamba pa ndege yopendekeka pali mphamvu w_x ndi f_kMphamvu ziwirizi zili ndi kukula kofanana koma mbali zosiyana kotero mphamvu yochokerapo = 0.

[Chingerezi: Mphamvu ya kukangana kosasinthasintha ndi kosinthasintha - mavuto ndi mayankho ]

4. Ngati kulemera kwa chinthucho ndi 4 kg, ngodya yopendekera ndi 30^o ndi kufulumira kwa mphamvu yokoka kwa 10 ms^-2 Chinthucho chidzapitirirabe kutsetsereka. Mtengo wapamwamba kwambiri wa coefficient of friction pakati pa chinthucho ndi plane yopendekera ndi…
Zokambirana
Amadziwika kuti:
m = 4 kg, g = 10 m/s²
Anafunsa: kuchuluka kwa kukangana kwakukulu?
Yankho:
Chofunikira cha static friction ndi chachikulu kuposa chofunikira cha kinetic friction, chifukwa chake tanthauzo la maximum friction coefficient ndi maximum static friction coefficient.
Zinthu sizimayenda molunjika:
Sinthani f_s mu equation 1 ndi f_s mu equation 2.
5. Ngati chinthu chiyikidwa pamalo osasunthika kenako n’kukokedwa ndi mphamvu, mphamvu yotsutsana yotchedwa friction imabuka. Kukula kwa mphamvu yotsutsana kumadalira...
A. kukhwima kwa pamwamba pa kukangana
B. kukula kwa mphamvu yachibadwa
C. kukhwima kwa malo okangana ndi kukula kwa mphamvu yachibadwa
D. kulemera kwa chinthu chomwe chikukokedwa
E. kukula kwa mphamvu yomwe imakoka chinthucho
Zokambirana
Kukangana kosasunthika kumagwira ntchito chinthu chikakokedwa koma sichikuyendabe. Kukangana kwa kinetic kumagwira ntchito chinthu chikayenda.
Ngati chinthucho chili pa mtunda wathyathyathya ndiye kuti N = w = mg
Ngati chinthucho chili pa mtunda wopendekeka ndiye N = w_y = w cos theta (onani chitsanzo cha vuto 1)
Kufotokozera: f_s = mphamvu yosasunthika yokhazikika, f_k = mphamvu ya kukangana kwa kinetic, N = mphamvu yachibadwa, w = mphamvu yokoka = kulemera kwa chinthu, g = kuthamanga chifukwa cha mphamvu yokoka.
Ngati vutoli likunena za malo osalala, ndiye kuti kukula kwa mphamvu yokangana kumadalira kukhwima kwa pamwamba (friction coefficient) ndi mphamvu yachibadwa (N).
Yankho lolondola ndi C.

6. Kukula kwa mphamvu yokangana pa chinthu chomwe chikuyenda pa mtunda wopendekeka kumadalira ...
A. kulemera kwa chinthu ndi liwiro la chinthucho
B. ngodya ya ndege yolunjika ku ndege yopingasa ndi liwiro la chinthucho
C. mphamvu yachibadwa ndi kuuma kwa pamwamba pa chinthucho
D. kulemera kwa chinthucho ndi ngodya ya ndege kupita ku ndege yopingasa
E. kukhwima kwa pamwamba pa ndege ndi liwiro la chinthucho
Zokambirana
Fomula ya mphamvu yayikulu yokhazikika yokhazikika pa ndege yopendekera:
Yankho lolondola ndi C.
Ngakhale kuti coefficient of friction imadalira kokha pa ngodya ya kupendekera ku horizontal (theta).