Mphamvu ya kupsinjika kwa static ndi kinetic - mavuto ndi mayankho

Mavuto omwe athetsedwera mu malamulo a Newton a kayendedwe - Mphamvu ya kukangana kwa static ndi kinetic

1. Chinthu chimakhala pansi mopingasa. Chiŵerengero cha kukangana kosasinthasintha ndi 0.4 ndipo kufulumira kwa mphamvu yokoka ndi 9.8 m/s ^2. Dziwani (a) Mphamvu yayikulu ya kukangana kosasinthasintha (b) Mphamvu yocheperako ya F

Mphamvu ya kukangana kosasinthasintha ndi koyenda bwino - mavuto ndi mayankho 1

Anakonza

Mphamvu ya kukangana kosasinthasintha ndi koyenda bwino - mavuto ndi mayankho 2

Zodziwika:

Kulemera (m) = 1 kg

Chiwerengero cha kukangana kosasinthasintha (μ _s) = 0.4

Kuthamanga kwa mphamvu yokoka (g) = 9.8 m/s ²

Kulemera (w) = mg = (1 kg)(10 m/s ² ) = 10 kg m/s ² = 10 Newtons

Mphamvu yachibadwa (N) = w = 10 Newtons

Akufuna:

(a) Mphamvu yayikulu ya kukangana kosasinthasintha (b) Mphamvu yochepa ya F

Yankho:

(a) Mphamvu yayikulu kwambiri ya kukangana kosasinthasintha

f _s= μ _sN

f _s= (0.4)(9.8 N) = 3.92 Newtons

(b) Mphamvu yochepa ya F

Ngati mphamvu ya F yagwiritsidwa ntchito pa chinthucho koma chinthucho sichinasunthidwe, ndiye kuti payenera kukhala mphamvu ya static friction yomwe ikugwiritsidwa ntchito ndi pansi pa chinthucho. Ngati chinthucho chiyamba kusuntha, mphamvu ya static friction yapitirira, payenera kukhala mphamvu ya kinetic friction. Chinthucho chimayamba kusuntha ngati F ndi yayikulu kuposa mphamvu yayikulu ya static friction.

Kotero mphamvu yocheperako ya F = mphamvu yayikulu ya kukangana kosasinthasintha = 3.92 Newtons.

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2. Bokosi la 1 kg limakokedwa pamalo opingasa ndi mphamvu F, kotero bokosilo likuyenda pa liwiro losasintha. Ngati kinetic friction coefficient ndi 0.1, dziwani kukula kwa mphamvu F! (g = 9.8 m/s ² )

Mphamvu ya kukangana kosasinthasintha ndi koyenda bwino - mavuto ndi mayankho 3

Zodziwika:

_{Chokwanira cha kinetic}friction ( μk ) = 0.1

Kulemera kwa bokosi (m) = 1 kg

Kuthamanga kwa mphamvu yokoka (g) = 9.8 m/s ²

Kulemera (w) = mg = (1 kg)(9.8 m/s ² ) = 9.8 kg m/s ² = 9.8 Newtons

Mphamvu yachibadwa (N) = w = 9.8 Newtons

Akufuna : F

Yankho:

Lamulo loyamba la Newton limati ngati palibe mphamvu yogwira ntchito pa chinthu, chinthu chilichonse chimapitirizabe kukhala chete, kapena liwiro losalekeza pamzere wowongoka.

Kotero ngati chinthucho chikuyenda pa liwiro losasintha , sipayenera kukhala mphamvu yeniyeni ( Σ F = 0) . Mphamvu F imagwiritsidwa ntchito pa chinthucho m'njira yoyenera kotero kuti mphamvu ya kinetic friction igwiritsidwe ntchito pa chinthucho kumanzere.

∑ F = 0

F – f _k= 0

F = f _k

Mphamvu ya kupsinjika kwa kinetic:

f _k = μ _kN = (0.1) (9.8 N) = 0.98 Newtons

chinthu chimayenda ndi liwiro losasintha, F = f _k= 0.98 Newtons

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3. Chinthu chimatsetsereka pansi pa mtunda wopendekeka ndi liwiro losasintha. Dziwani kuchuluka kwa kinetic friction coefficient ( _μk) . g = 9.8 m/s ²

Mphamvu ya kukangana kosasinthasintha ndi koyenda bwino - mavuto ndi mayankho 4

Anakonza

Mphamvu ya kukangana kosasinthasintha ndi koyenda bwino - mavuto ndi mayankho 5

w = kulemera, w _x= gawo lopingasa la kulemera, mfundo motsatira kupendekera, w _y= gawo loyima la kulemera, lolunjika ku ndege yopendekera, N = mphamvu yachibadwa, f _k= mphamvu ya kukangana kwa kinetic.

Zodziwika:

Kulemera (m) = 1 kg

Kuthamanga kwa mphamvu yokoka (g) = 9.8 m/s ²

kulemera (w) = mg = (1 kg)(9.8 m/s ² ) = 9.8 kg m/s ² = 9.8 Newtons

w _x= w sin 30 ^o= (9.8 N)(0.5) = 4.9 Newtons

w _y= w cos 30 ^o = (9.8 N)(0.5) √ 3 = 4.9 √ 3 Newtons

Mphamvu yachibadwa (N) = w _y= 4.9 √ 3 Newtons

Kufunidwa : kinetic friction coefficient ( μk ₎

Yankho:

Chinthucho chimatsika pansi pa mtunda wopendekeka ndi liwiro losalekeza kotero kuti mphamvu yonse = 0.

∑ F = 0

w _x– f _k= 0

w _x= f _k

w _x= μ _kN

5 = μ _k( 5 √ 3 )

μ _k= 5 / 5 √ 3

μ _k= 1 / √ 3

μ _k= 0.58

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