Tsela e sekametseng - mathata le litharollo

Tsela e sekametseng - mathata le litharollo

1. Boima ba boloko ke 5 kg, ho potlaka ka lebaka la matla a khoheli = 9.8 m/s ² , tan 37 ^o = 3/4. Potlako ea boloko ke eng?

tharollo

Tse tsejoang:

boima (m) = 5 kg

ho potlaka ka lebaka la matla a khoheli (g) = 10 m/s ²

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

x = 3

Bophahamo ba sefofane se sekametseng (y) = 4

Bolelele ba bokaholimo ba sefofane bo sekametseng (l) = 5

Ho batloa : ho potlakisa ha thipa (a)?

Tharollo:

Boloko bo potlakiswa ke matla a w _x . Sefapano se sekametseng se boreleli kahoo ha ho na matla a khohlano.

w _x = w sin θ = (w)(y / z)

w _x = (50)(4/5)

w _x = 40 Newton

Ho potlaka ha boloko (a) ?

ΣF = ma

w _x = ma

40 = (5) a

a = 40/5

a = 8 m/s ²

2. Tloko qalong ha e phomotse, ebe e potlakiswa ho ya hodimo e bapile le bokahodimo ba sefofane bo sekametseng. Boima ba Tloko = 8 kg, coefficient ya static friction µ _s = 0.5 le angle θ = 45 ^o . Boholo ba matla F ke bofe e le hore toko e potlakiswe.

Tse tsejoang:

Koefficient ea khohlano e sa fetoheng (µs ₎ = 0.5

Sekhutlo (θ) = 45 ^o

Ho potlaka ka lebaka la matla a khoheli (g) = 10 m/s ²

Boima ba Block (m) = 8 kg

Boima ba boloko (w) = mg = (8 kg)(10 m/s ² ) = 80 kg m/s ² = 80 Newtons

Ho batloa: Boholo ba matla F

Tharollo:

Thibela qala ho potlakisa haeba F ≥ w_x + f_s.

Karolo e otlolohileng ea boima :

w _x = w sebe θ = (80)(sebe 45) = (80)(0.5√2) = 40√2

Karolo e otlolohileng ea boima:

w _y = w cos θ = (80)(cos 45) = (80)(0.5√2) = 40√2

Matla a tloaelehileng :

N = w _y = 40√2

Matla a khohlano e sa fetoheng:

f _s = µ _s N = (0.5)(40√2) = 20√2

Boholo ba matla F:

F ≥ w _x + f _s

F ≥ 40√2 + 20√2

F ≥ 60√2 Newton

3. Boima ba boloko ke 8 kg. Matla a fokolang a hlokahalang ho tshwara boloko e le hore boloko bo se ke ba thella ke … (sin 37 ^o = 0.6, cos 37 ^o = 0.8, g = 10 ms ^-2 , µ _k = 0.1)

Tse tsejoang:

Boima ba boloko (m) = 8 kg

Ho potlaka ka lebaka la matla a khoheli (g) = 10 m/s ²

Boima ba boloko (w) = mg = (8)(10) = 80 Newtons

Sebe sa 37 ^o = 0.6

Cos 37 ^o = 0.8

Khokahano ea kinetic friction (µ _k ) = 0.1

Matla a tloaelehileng (N) = w _y = w cos 37 ^o = (80)(0.8) = 64 Newtons

Ho batloa: Boholo ba matla F

Tharollo:

Boloko ha bo thelle fatshe haeba F = w _x

Karolo e otlolohileng ea boima e bapileng le bokaholimo bo sekametseng:

w _x = w sebe θ = (80)(sebe 37) = (80)(0.6) = 48

f _k = µ _k N = (0.1) (64) = 6.4

Bonyane ba matla F e le hore boloko bo se ke ba thella fatshe:

F + f _k – w _x = 0

F = w _x – f _k = 48 – 6.4 = 41.6 Li-Newton

4. Boloko ba 5-kg bo hulwa hodima sefofane se sekametseng ka matla a 71 N (g = 10 ms ^-2 , sin 37 ^o = 0.6, cos 37 ^o = 0.8). Haeba coefficient ya matla a kgohlano pakeng tsa boloko le sefofane se sekametseng e le 0.4, ho potlakisa boloko ke eng.

Tse tsejoang:

Boima ba ntho (m) = 5 kg

Ho potlaka ka lebaka la matla a khoheli (g) = 10 m/s ²

boima ba boloko (w) = mg = (5)(10) = 50 Newtons

Matla F = 71 Newton

Sebe sa 37 ^o = 0.6

Cos 37 ^o = 0.8

Khokahano ea khohlano = 0.4

Ho batloa : Ho potlakisa boloko (a)

Tharollo:

Karolo e otlolohileng ea boima :

w _x = w sebe θ = (50)(sebe 37) = (50)(0.6) = 30

Karolo e otlolohileng ea boima :

w _y = w cos θ = (50)(cos 37) = (50)(0.8) = 40

Matla a tloaelehileng:

N = w _y = 40

Matla a khohlano ea kinetic:

f _k = µ _k N = (0.4)(40) = 16

Matla a marang-rang:

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

Ho potlakisa ntho:

a = ∑F / m = 25 / 5 = 5 m/s ²

5. Lebokose la 500-N le phahamisetsoang terakeng ka sefofane se sekametseng, joalo ka ha ho bontšitsoe setšoantšong se ka tlase. Haeba bophahamo ba teraka e le limithara tse 1.5, fumana boholo ba matla a ho tsamaisa lebokose.

Tse tsejoang:

boima ba lebokose (w) = 500 Newtons

bophahamo ba teraka (h) = limithara tse 1.5

bolelele ba sefofane se sekametseng (l) = limithara tse 3

Ho batloa: Boholo ba matla a ho tsamaisa lebokose (F)

Tharollo:

Sebe θ = opp / hyp = 1.5 limithara / 3 limithara = 1.5 / 3 = 0.5

Matla (F) a hlokahalang ho tsamaisa lebokose, a tshwanang le karolo e rapameng ya boima e bapileng le sefofane se sekametseng (w _x ).

w _x = w sebe θ = (500 N)(0.5) = 250 N

1. Sefofane se sekametseng ke eng, hona se nolofatsa mosebetsi joang?
   • karabo: Sefofane se sekametseng ke bokaholimo bo bataletseng bo behiloeng ka sekhutlo (ntle le sekhutlo se nepahetseng) ho ea holim'a bokaholimo bo otlolohileng. E nolofatsa mosebetsi ka ho lumella matla ho sebelisoa sebakeng se selelele ho hlola matla a hanyetsang, hangata ho fokotsa boholo ba matla a hlokahalang ho phahamisa kapa ho theola ntho.
2. Sekhutlo sa tshekamelo se ama matla a hlokahalang ho tsamaisa ntho hodimo sefofaneng jwang?
   • karabo: Ha sekhutlo sa ho sekamela se tebile, matla a hlokahalang ho tsamaisa ntho hodimo a ba maholo. Ha sekhutlo se fokotseha, matla a hlokahalang a a fokotseha empa a sebediswa sebakeng se selelele.
3. Ke hobane'ng ha ho le bonolo ho sutumelletsa lebokose le boima ho nyolosa ramp ho feta ho le phahamisa ka ho otloloha?
   • karabo: Ho sutumelletsa lebokose hodimo ho ramp (sebaka se sekametseng) ho arola boima ba lebokose hole haholo, ho fokotsa matla a hlokahalang ka nako efe kapa efe. Ho le phahamisa ka ho otloloha ho hloka hore motho a lwantshe boima bohle ba lebokose ka ho toba, e leng se hlokang matla a maholo haholo.
4. Bolelele ba sefofane se sekametseng bo amana jwang le matla a hlokahalang ho tsamaisa ntho hodimo sefofaneng?
   • karabo: Ha sefofane se sekametseng se le selelele (bakeng sa bophahamo bo tsitsitseng), matla a fokolang a hlokahala ho tsamaisa ntho hodimo. Leha ho le jwalo, matla a lokela ho sebediswa sebakeng se selelele.
5. Haeba khohlano e hlahisoa sebakeng se sekametseng, e ama motsamao oa ntho e ho sona joang?
   • karabo: Khohlano e hanyetsa motsamao oa ntho. Haeba ntho e sutumelletsoa holimo sebakeng se sekametseng, khohlano e theohela tlase, e eketsa matla a hlokahalang ho tsamaisa ntho. Haeba ntho e theoha sefofaneng, khohlano e liehisa ho theoha ha eona.
6. Ke hobane'ng ha basebetsi ba sebelisa lifofane tse sekametseng ho kenya lintho tse boima literakeng?
   • karabo: Ho sebelisa sefofane se sekametseng (ramp) ho lumella basebetsi ho sebelisa matla a manyane sebakeng se selelele ho jara lintho tse boima, e leng se etsang hore mosebetsi o laolehe habonolo le hore o se ke oa ba boima ho feta ho phahamisa lintho ka ho otloloha.
7. Boima ba ntho bo amana jwang le tshekamelo ya yona ya ho thella fatshe ka sefofane se sekametseng?
   • karabo: Karolo ea boima ba ntho e sebetsang ka ho lekana le bokaholimo ba sefofane se sekametseng e etsa hore e thelle. Ha ntho e le boima, karolo ena ea boima e ba kholoanyane, 'me ka hona, tšekamelo ea hore ntho e thelle fatše e ba kholoanyane.
8. Matla a tloaelehileng a bapala karolo efe sebakeng se sekametseng?
   • karabo: Matla a tloaelehileng a sebetsa ka ho otloloha holim'a sefofane se sekametseng. A ikarabella bakeng sa bongata ba matla a khohlano pakeng tsa ntho le sefofane kaha khohlano hangata e lekana le matla a tloaelehileng.
9. Ke hobane'ng ha lehlabathe kapa lehlohlojane li ka beoa sebakeng se sekametseng nakong ea serame?
   • karabo: Lehlabathe kapa lehlohlojane le eketsa matla a khohlano pakeng tsa sefofane se sekametseng le lintho (tse kang lieta kapa mabili) tse kopanang le lona. Khohlano ena e eketsehileng e thusa ho thibela ho thella nakong ea maemo a leqhoa kapa a mongobo.
10. Haeba bolo e phuthoa ka tsela e sekametseng ebe e kgutlela tlase, na e tla fihla lebelong la yona la pele nakong eo e kgutlelang moo e qadileng teng, e hlokomoloha ho hanyetsa moya le kgohlano?

• karabo: E, ha ho se na khanyetso ea moea le khohlano, matla a ka bang teng a bolo ntlheng ea eona e phahameng ka ho fetisisa a tla fetoha ka botlalo ho ea ho matla a kinetic ha e theoha, e leng se e lumellang ho fihlela lebelo la eona la pele nakong eo e khutlelang moo e qalang teng ka lebaka la paballo ea matla.