Chitsanzo cha mafunso okhudza Plane Yopendekeka

Zitsanzo 9 za Mafunso Okhazikika

Phunzirani mfundo zokhudza malamulo a Newton , mphamvu yachibadwa ndi mphamvu yokangana kuti mumvetse bwino nkhani ya funsoli.

1. Chipolopolo cha 5 kg chimatulutsidwa pamalo osalala monga momwe zasonyezedwera pachithunzichi! (g = 10 ms ⁻² ndi tg 37 ^o = 3/4). Kuthamanga kwa chipolopolocho ndi...

A. 4,5 ms^-2

B. 6,0 ms ⁻²

C. 7,5 ms ⁻²

D. 8,0 ms ⁻²

E. 10,0 ms ⁻²

Zokambirana

Amadziwika kuti:

m = 5 kg, g = 10 m/s ²

w = mg = (5)(10) = 50 N

kutalika kwa mbali ya pansi = 4

kutalika kwa mbali yoyimirira = 3

Popeza mbali ya pansi = 4 ndi mbali yoyimirira = 3 ndiye hypotenuse = 5. Mutha kutsimikizira izi pogwiritsa ntchito njira ya Pythagorean.

Funso: kufulumira kwa block (a)?

Yankho:

Mphamvu yomwe imapangitsa kuti chipikacho chizisuntha ndi w _x . Mzere wopendekera ndi wosalala kotero palibe kukangana.

w_x = uchimo θ = (w)(mbali yowongoka / hypotenuse)

w _x = (50)(3/5)

w _x = 30 Newton

Kodi kuthamanga kwa (a) kwa chipikacho ndi chiyani?

Σ F = ma

w _x = ma

30 = (5) a

a = 30 / 5

a = 6 m/s ²

Yankho lolondola ndi B.

2. Yang'anani chithunzi! Chipikacho chimayikidwa pamalo opumulira, kenako chimakokedwa ndi mphamvu F mmwamba molingana ndi malo opendekera. Kulemera kwa chipikacho ndi 8 kg, coefficient of friction µ _s = 0,5 ndi θ = 45 ^o . Kuti chipikacho chiyende bwino mmwamba, mphamvu F iyenera kukhala….

A. 40 N

B. 60 N

C. 60√2 N

D. 80 N

E. 80√2 N

Zokambirana

Amadziwika kuti :

Chokwanira cha kusinthasintha kosasunthika (µs ₎ = 0,5

Ngodya (θ) = 45 ^o

Kuthamanga chifukwa cha mphamvu yokoka (g) = 10 m/s ²

Kulemera kwa chipika (m) = makilogalamu 8

Kulemera kwa chipika (w) = mg = (8 kg)(10 m/s ² ) = 80 kg m/s ² = 80 Newtons

Funso : Kukula kwa mphamvu F kotero kuti chipikacho chizipita mmwamba

Yankho :

Chipikacho chidzakwera mmwamba ngati F ≥ w _x + f _s.

Gawo la mphamvu yokoka lofanana ndi ndege yopendekera :

w _x = w tchimo θ = (80)(tchimo 45) = (80)(0,5√2) = 40√2

Gawo la mphamvu yokoka lolunjika ku ndege yopendekeka :

w _y = w cos θ = (80)(cos 45) = (80)(0,5√2) = 40√2

Mphamvu yachibadwa :

N = w _y = 40√2

Mphamvu yosasunthika yokangana :

f _s = µ _s N = (0,5) (40√2) = 20√2

Kukula kwa mphamvu F kotero kuti chipikacho chizipita mmwamba :

F ≥ w _x + f _s

F ≥ 40√2 + 20√2

F ≥ 60√2 Newton

Yankho lolondola ndi C.

3. Chipika cholemera makilogalamu 8 chimayikidwa pamalo otsetsereka mozungulira monga momwe chithunzichi chikusonyezera. Mphamvu yochepa yakunja yomwe imafunika kuti chipikacho chisatsike pansi ndi… (sin 37 ^o = 0,6, cos 37 ^o = 0,8, g = 10 ms ^-2 , µ _k = 0,1)

A. 6,4 N

B. 4,6 N

C. 48,5 N

D. 54,4 N

E. 68,8 N

Zokambirana

Amadziwika kuti :

Kulemera kwa chipika (m) = 8 kg

Kuthamanga chifukwa cha mphamvu yokoka (g) = 10 m/s ²

Kulemera kwa chipika (w) = mg = (8)(10) = 80 Newton

Tchimo 37 ^o = 0,6

Cos 37 ^o = 0,8

Koyefifiti ya kukangana kwa kinetic (µ _k ) = 0,1

N = w _y = w cos 37 ^o = (80)(0,8) = 64 Newtons

Funso : Mphamvu yochepa yakunja (F) yofunikira kuti ithandizire chipikacho kuti chipikacho chisagwedezeke.

Yankhani :

Chipikacho sichimatsika pansi ngati F = w _x

Gawo la mphamvu yokoka lofanana ndi ndege yopendekera :

w _x = w tchimo θ = (80) (tchimo 37) = (80) (0,6) = 48

f _k = µ _k N = (0,1) (64) = 6,4

Mphamvu yocheperako F kuti chipikacho chisagwere pansi :

F + f _k – w _x = 0

F = w _x – f _k = 48 – 6,4 = 41,6 Newtons

4. Chinthu cholemera makilogalamu 5,0 chimakokedwa ndi chingwe mmwamba mwa ndege yokhotakhota ndi mphamvu ya 71 N (g = 10 ms s ^-2 , sin 37 ^o = 0,6, cos 37 ^o = 0,8). Ngati coefficient of friction pakati pa chinthucho ndi ndege ndi 0,4, kuthamanga komwe kumachitika ndi chinthucho ndi…

A. 0,5 ms^-2

B. 2 ms ^-2

C. 2,5 ms ^-2

D. 3 ms ^-2

E. 5 ms ^-2

Zokambirana

Amadziwika kuti :

Kulemera kwa chinthu (m) = 5 kg

4. Mafunso a Mayeso a Dziko Lonse a SMA Fizikisi a 2012/2013 SA 67 Nambala 5

Chinthu cholemera makilogalamu 5,0 chimakokedwa ndi chingwe mmwamba mwa ndege yokhotakhota ndi mphamvu ya 71 N (g = 10 ms s ^-2 , sin 37 ^o = 0,6, cos 37 ^o = 0,8). Ngati coefficient of friction pakati pa chinthucho ndi ndege ndi 0,4, kuthamanga komwe kumachitika ndi chinthucho ndi…

A. 0,5 ms ^-2

B. 2 ms ^-2

C. 2,5 ms ^-2

D. 3 ms ^-2

E. 5 ms ^-2

Zokambirana

Amadziwika kuti :

Kulemera kwa chinthu (m) = 5 kg

Kuthamanga chifukwa cha mphamvu yokoka (g) = 10 m/s ²

Kulemera kwa chinthu (w) = mg = (5)(10) = 50 Newtons

Mphamvu F = 71 Newton

Tchimo 37 ^o = 0,6

Cos 37 ^o = 0,8

Koyenera ya kukangana = 0,4

Funso : Kufulumizitsa chinthu (a)

Yankho :

Mphamvu Yotsatira

Choyamba werengani mphamvu yochokera pa chinthucho.

Gawo la mphamvu yokoka lofanana ndi ndege yopendekera :

w _x = w tchimo θ = (50) (tchimo 37) = (50) (0,6) = 30

Gawo la mphamvu yokoka yolunjika ku ndege yopendekera :

w _y = w cos θ = (50) (cos 37) = (50) (0,8) = 40

Kalembedwe kabwinobwino :

N = w _y = 40

Mphamvu ya kukangana kwa kinetic :

f _k = µ _k N = (0,4)(40) = 16

Mphamvu yochokera ku chinthu chomwe chimagwira ntchito pamalo opendekeka:

∑ F = F – w _x – f _k = 71 – 30 – 16 = 25 Newtons

Kuthamanga kwa chinthu

Kuthamanga kwa chinthu kumawerengedwa pogwiritsa ntchito njira yachiwiri ya lamulo la Newton:

a = ∑F / m = 25 / 5 = 5 m/s ²

Yankho lolondola ndi E.

5.
Yang'anani chithunzicho! Poyamba chipika chimakhala pamalo opumulira, kenako chimakokedwa ndi mphamvu yopita mmwamba F yofanana ndi ndege yopendekeraKulemera kwa chipikacho ndi 8 kg, coefficient of friction ndi µ_s = 0,5 ndi θ = 45^oKuti chipikacho chikwere mmwamba, mphamvu F iyenera kukhala….

A. 40 N
B. 60 N
C. 60√2 N
D. 80 N
E. 80√2 N

Zokambirana
Ndizodziwika kuti :
Koefficient kukangana kosasinthasintha (µ_s= = 0,5
Ngodya (θ) = 45^o
Kuthamanga chifukwa cha mphamvu yokoka (g) = 10 m/s²
Kulemera kwa chipika (m) = makilogalamu 8
Kulemera kwa chipika (w) = mg = (8 kg)(10 m/s²) = 80 kg m/s² = 80 Newton
Anafunsa : Kukula kwa mphamvu F kotero kuti chipikacho chizipita mmwamba
Yankhani :

Chipika cholondola chidzakwera mmwamba ngati F ≥ w_x + f_s.
Gawo la mphamvu yokoka lofanana ndi ndege yopendekera :
w_x = w uchimo θ = (80)(tchimo 45) = (80)(0,5√2) = 40√2
Gawo la mphamvu yokoka lolunjika ku ndege yopendekeka :
w_y = w cos θ = (80)(cos 45) = (80)(0,5√2) = 40√2
Mphamvu yachibadwa :
N = w_y = 40√2
Mphamvu yosasunthika yokangana :
f_s = µ_s N = (0,5)(40√2) = 20√2
Kukula kwa mphamvu F kotero kuti chipikacho chizipita mmwamba :
F ≥ w_x + f_s
F ≥ 40√2 + 20√2
F ≥ 60√2 Newton
Yankho lolondola ndi C.

6.
Chipika cholemera makilogalamu 8 chimayikidwa pamalo otsetsereka mozungulira monga momwe chithunzi chili pansipa chikusonyezera. Mphamvu yochepa yakunja yomwe imafunika kuti chipikacho chisatsike pansi ndi… (chimo 37)^o = 0,6, cos 37^o = 0,8, g = 10 ms^-2, µ_k = 0,1)

A. 6,4 N
B. 4,6 N
C. 48,5 N
D. 54,4 N
E. 68,8 N

Zokambirana
Ndizodziwika kuti :
Kulemera kwa chipika (m) = 8 kg
Kuthamanga chifukwa cha mphamvu yokoka (g) = 10 m/s²
Kulemera kwa chipika (w) = mg = (8)(10) = 80 Newton
Tchimo 37^o = 0,6
kodi 37^o = 0,8
Koyenera ya kukangana kwa kinetic (µ_k= = 0,1
Anafunsa : Mphamvu yochepa yakunja (F) yomwe imagwira chipikacho kuti chipikacho chisagwedezeke pansi
Yankhani :
Chipikacho sichimatsika pansi ngati F = w_x
Gawo la mphamvu yokoka lofanana ndi ndege yopendekera :
w_x = w uchimo θ = (80)(tchimo 37) = (80)(0,6) = 48
f_k = µ_k N = (0,1)(64) = 6,4
Mphamvu yocheperako F kuti chipikacho chisagwere pansi :
F + f_k - w_x = 0
F = w_x - f_k = 48 – 6,4 = 41,6 Newtons

7.
Chinthu cholemera makilogalamu 5,0 chimakokedwa ndi chingwe mmwamba mwa malo otsetsereka ndi mphamvu ya 71 N (g = 10 ms).^-2, uchimo 37^o = 0,6, cos 37^o = 0,8). Ngati coefficient of friction pakati pa chinthu ndi ndege ndi 0,4, kuthamanga komwe kumachitika ndi chinthucho ndi…
A. 0,5 ms^-2
B. 2 ms^-2
C. 2,5 ms^-2
D. 3 ms^-2
E. 5 ms^-2
Zokambirana
Ndizodziwika kuti :
Kulemera kwa chinthu (m) = 5 kg
Kuthamanga chifukwa cha mphamvu yokoka (g) = 10 m/s²
Kulemera kwa chinthu (w) = mg = (5)(10) = 50 Newtons
Mphamvu F = 71 Newton
Tchimo 37^o = 0,6
kodi 37^o = 0,8
Koyenera ya kukangana = 0,4
Anafunsa Kufulumizitsa chinthu (a)
Yankhani :
Mphamvu Yotsatira
Choyamba werengani mphamvu yochokera pa chinthucho.
Gawo la mphamvu yokoka lofanana ndi ndege yopendekera :
w_x = w uchimo θ = (50)(tchimo 37) = (50)(0,6) = 30
Gawo la mphamvu yokoka lolunjika ku ndege yopendekeka :
w_y = w cos θ = (50)(cos 37) = (50)(0,8) = 40
Mphamvu yachibadwa :
N = w_y = 40
Mphamvu ya kukangana kwa kinetic :
f_k = µ_k N = (0,4)(40) = 16
Mphamvu yochokera ku chinthu chomwe chimagwira ntchito pamalo opendekeka:
∑F = F – w_x - f_k = 71 – 30 – 16 = 25 Newtons
Kuthamanga kwa chinthu
Kuthamanga kwa chinthu kumawerengedwa pogwiritsa ntchito njira yachiwiri ya lamulo la Newton:
a = ∑F / m = 25 / 5 = 5 m/s²
Yankho lolondola ndi E.

8. Yang'anani chithunzi! Chipikacho chimayikidwa pamalo opumulira, kenako chimakokedwa ndi mphamvu F mmwamba molingana ndi malo opendekera. Kulemera kwa chipikacho ndi 2 kg, coefficient of static friction = 0,3 ndi ngodya = 45 ^o . Kuti chipikacho chiyende bwino mmwamba, mphamvu F iyenera kukhala… g = 10 m/s ²

Zokambirana
Amadziwika kuti:
m = 2 kg, g = 10 m/s², = 45^o, mu_s = 0,3
Funso: Kuti chipikacho chiyende bwino mmwamba, kodi mphamvu F ndi yaikulu bwanji?
Yankho:

Chidziwitso: F = mphamvu yokoka, w = mphamvu yokoka, w_x = gawo la kulemera kwa chipika chofanana ndi pamwamba pa ndege yopendekeka, w_y = gawo la kulemera kwa chipikacho molunjika pamwamba pa ndege yopendekera, N = mphamvu yachibadwa, f_s = mphamvu yokangana yosasinthasintha.

Mu funsoli, coefficient of static friction imadziwika, izi zikutanthauza kuti pamwamba pa ndege yopendekeka ndi yolimba kotero kuti pali mphamvu yokangana yomwe imaletsa kuyenda kwa block.
Kuti chipikacho chikwere mmwamba, mphamvu ya F iyenera kukhala yofanana ndi w._x +f_sChinthucho chimapita mmwamba pamene F ndi yayikulu kuposa w_x +f_s.

w = mg = (2)(10) = 20 Newton
w_x = w sin 45^o = (20)(½ √2) = 10√2 Ma Newton
w_y = w cos 45^o = (20)(½√2) = 10√2 Ma Newton
N = w_y = 10√2
f_s = μ_s N = (0,3)(10√2) = 3√2 Ma Newton

Kotero kuti chipikacho chizipita mmwamba:
F = w_x +f_s = 10√2 + 3√2= 13√2 Ma Newton
Yankho lolondola ndi C.

9. Chinthu cholemera makilogalamu awiri chimayikidwa pamalo opendekeka monga momwe chithunzi chili pansipa chikusonyezera. Ngati coefficient of static friction pakati pa block ndi malo opendekeka ndi 0,2√3 ndipo g = 10 ms ^–2 , ndiye kuti mphamvu yochokerapo yomwe imasuntha chinthucho ndi…

Zokambirana
Amadziwika kuti:
m = 2 kg, g = 10 m/s², = 30^o, mu_s = 0,2√3
Anafunsa: Mphamvu yochokerapo yomwe imasuntha chinthu?

Yankho:

Kukangana nthawi zonse kumalepheretsa kuyenda kwa chinthu, motero njira ya mphamvu yokangana imawonetsedwa mosiyana ndi njira ya kayendetsedwe ka chinthucho. Chinthucho chimaganiziridwa kuti chikuyenda pansi, kotero mphamvu yokangana imawonetsedwa ngati mmwamba. Chinthucho chimaganiziridwa kuti chikuyenda pansi chifukwa palibe mphamvu yomwe imachikoka mmwamba.
w = mg = (2)(10) = 20 Newton
w_x = w sin 30^o = (20)(½) = 10 Newton
w_y = w cos 30^o = (20)(½ √3) = 10√3 Ma Newton
N = w_y = 10√3 Newton
f_s = μ_s N = (0,2√3)(10√3) = (2)(3) = 6 Newtons
Mphamvu yomwe imasuntha chinthu ndi iyi:
F = w_x - f_s = 10 – 6 = 4 Newtons
w_x chachikulu kuposa f_s kotero chinthucho chimapita pansi, molunjika ku w_x.
Yankho lolondola ndi A.

Gwero la funso:

Mafunso a National Examination Physics a Senior High School/Vocational High School