Molao-motheo oa matla a mosebetsi le mechine - mathata le litharollo

1. Lebokose la boima ba 2 kg le theoha ka lebelo ho tloha ho 10 m/s ho ea phomolong. Coefficient ea kinetic friction ke 0.2. Potlako e bakoang ke matla a khoheli ke 10 m/s ^2. Boholo ba ho falla ke bofe?

Tsejoang;

Boima (m) = 2 kg

Lebelo la pele (vo _o ) = 10 m/s

Lebelo la ho qetela (v _t ) = 0 m/s

Koefficient ea ho ferekana ha kinetic ( _μk ) = 0.2

Boima (w) = mg = (1 kg)(10 m/s ² ) = 10 kg m/s ² = 10 N

Ho batloa: Boholo ba ho falla (d)

Tharollo:

Molao-motheo oa matla a mosebetsi le mechine :

W _nc = ΔEM

W _nc = ΔEK + ΔEP

W _nc = ½ m (v _t ² – vo ₂ ⁾ + mgh

W _nc = mosebetsi o etsoang ke matla a sa laoleheng a sebetsang nthong eo

ΔEK = phetoho ea matla a kinetic

ΔEP = phetoho ea matla a ka bang teng

m = boima

v = lebelo

g = ho potlaka ka lebaka la matla a khoheli

h = phetoho bophahamong

Phetoho bophahamong h = 0 kahoo ΔEP = 0

W _nc = ΔEK

Mosebetsi o etsoang ke matla a sa batleng mekhoa ea khale:

W _nc = -F _c d = – μ _k N d = – μ _k wd = – μ _k mgd

W _nc = -(0.2)(2)(10)(s)

W _nc = – (4)(2)

Letšoao la ho tlosa le bontša hore tataiso ea matla a khohlano ea kinetic e fapane le tataiso ea ho falla.

Phetoho ea matla a kinetic:

ΔEK = ½ m (v _t ² – v _o ² ) = ½ (2) (0 – 10 ² ) = 0 – 100 = -100

Boholo ba ho falla:

W _nc = ΔEK

– 4 s = – 100

s = -100/-4

s = 25 m

2. Boloko bo thella fatshe hodima sefofane se sekametseng. Coefficient ya kinetic friction ke 0.4. Ho potlaka ka lebaka la matla a khoheli ke g = 10 ms ^-2 . Fumana lebelo la ho qetela ha boloko bo otla fatshe.

Tse tsejoang:

Bolelele ba pele (h _o ) = 6 m

Bolelele ba ho qetela (h _t ) = 0 m

Lebelo la pele (v _o ) = 0

Koefficient ea ho ferekana ha kinetic ( _μk ) = 0.4

Ho potlaka ka lebaka la matla a khoheli (g) = 10 ms ^-2

cos θ = 8/10

Karolo e otlolohileng ea boima = w _y = w cos θ = mg cos θ = m (10) (8/10) = m (10)(4/5) = m (40/5) = 8 m

Matla a tloaelehileng = N = w _y = 8 m

Matla a kgohlano ya kinetic = f _k = μ _k N = μ _k w _y = (0.4)(8 m) = 3.2 m

Ho batloa: Lebelo la ho qetela (v _t )

Tharollo:

Molao-motheo oa matla a mosebetsi le mechine:

W _nc = Δ EM

W _nc = Δ EK + Δ EP

Phetoho ea matla a kinetic:

ΔEK = 1/2 m (v_t² - v_o²) = 1/2 m (v_t² - 0) = 1/2 mv_t²

Phetoho ea matla a ka bang teng:

Δ EP = mg (h _t – ho ₎ = m (10)(0-6) = m (10)(-6) = – 60 m

Mosebetsi o etsoang ka matla a moferefere oa kinetic:

W _nc = – f _ks = – ( 3.2 m)(10) = – 32 m

Letšoao la ho tlosa le bontša hore tataiso ea matla a khohlano ea kinetic e fapane le tataiso ea ho falla.

Lebelo la ho qetela (v _t ):

W _nc = Δ EK + Δ EP

– 32 m = 1/2 mv _t ² – 60 m

– 32 m = m (1/2 v _t ² – 60)

– 32 = 1/2 v _t ² – 60

– 32 + 60 = 1/2 v _t ²

28 = 1/2 v _t ²

2 (28) = v _t ²

56 = v _t ²

v _t = √4.14

v _t = 2 √14 ms ^-1

3. Boloko bo thella fatshe sefofaneng se sekametseng ka tsela e sa tsitsang. Lebelo la pele ke 0 m/s mme lebelo la ho qetela ke 10 ms ^-1 . Haeba matla a kgohlano ya kinetic e le 2 N mme ho potlaka ka lebaka la matla a kgoheli g = 10 ms ^-2 , bolelele (h) ke eng?

Tse tsejoang:

Boima (m) = 1 kg

Lebelo la pele (v _o ) = 0 (phomolo ea boloko)

Lebelo la ho qetela (v _t ) = 10 ms ^-1

Bolelele ba pele (h _o ) = h

Bolelele ba ho qetela (h _t ) = 0

Matla a khohlano ea kinetic (f _k ) = 2 N

Ho potlaka ka lebaka la matla a khoheli (g) = 10 ms ^-2

Ho batloa: Bolelele (h)

Tharollo:

Mosebetsi o etsoang ka matla a moferefere oa kinetic:

W _nc = – f _ks = – (2 )(15) = – 30

Letšoao la ho tlosa le bontša hore tataiso ea matla a khohlano ea kinetic e fapane le tataiso ea ho falla.

Phetoho ea matla a kinetic:

ΔEK = 1/2 m (v_t² - v_o²) = 1/2 (1)(10² - 0) = 1/2 (10²) = 1/2 (100= 50

Phetoho ea matla a ka bang teng:

Δ EP = mg (h _t – ho ₎ = (1)(10)(0-h) = (10)(-h) = -10 h

Molao-motheo oa matla a mosebetsi le mechine:

W _nc = Δ EK + Δ EP

– 30 = 50 – 10 dihora

Lihora tse 10 = 50 + 30

Lihora tse 10 = 80

h = 80/10

h = 8 m

4Haeba boloko bo theoha ka tsela e sekametseng hanyane, joale….
A. Mosebetsi o etsoang ke matla a khoheli holim'a boloko o moholo ho feta phetoho ea matla a ka bang teng a boloko.
B. Matla a mechini aa eketseha
C. Bongata ba matla a kinetic le matla a ka bang teng a fokotsehile
D. Mosebetsi o etsoa ke matla a khohlano a lekanang le phetoho ea matla a kinetic a block
tharollo

A e fositse

Mosebetsi o etsoang ke matla a khoheli holim'a boloko o lekana le phetoho ea matla a khoheli a boloko.

B o fositse

Haeba sefofane se nang le mola o ka hare se boreleli, matla a mechini a boloko ha a fetohe. Ha se le ka holimo ho sefofane se sekametseng mme se sa sisinyehe, matla a mechini a boloko a lekana le matla a khoheli a khoheli. Boloko bo ntse bo phomotse kahoo matla a sona a kinetic ke lefela. Ha se theohela tlase sefofaneng se sekametseng, bophahamo ba boloko boa fokotseha kahoo matla a khoheli a khoheli le ona aa fokotseha. Matla a khoheli a fokotseha hobane a fetoha matla a kinetic. Le hoja matla a khoheli a fetoha matla a kinetic empa matla a mechini a lula a le teng.

Haeba sefofane se sekametseng se le thata, matla a mechini a boloko aa fokotseha ka lebaka la mosebetsi o mobe o etsoang ke matla a khohlano. Matla a khohlano ke matla a sa bolokeng. Mosebetsi o etsoang ke matla a sa bolokeng nthong o etsa hore matla a mechini a ntho a fokotsehe.

C e nepahetse

Sefofane se sekametseng se makukuno kahoo ho na le matla a khohlano a phephetsang motsamao oa block. Matla a khohlano ke matla a sa bolokeng. Matla a mosebetsi-mechanical a theorem a bolela hore mosebetsi o etsoang ke matla a sa bolokeng (mohlala, matla a khohlano) o lekana le phetoho ea matla a mechini. Leetong lena, matla a mechini aa fokotseha.

Matla a mechine a boloko = matla a khoheli a ka bang teng + matla a kinetic.

D o fositse.

Mosebetsi o etsoang ke matla a khohlano bolokong o lekana le phetoho ea matla a mechini a boloko, eseng phetoho ea matla a kinetic a boloko. Ke 'nete hore matla a khohlano a phephetsa motsamao oa boloko kahoo a fokotsa lebelo la boloko 'me a fokotsa matla a kinetic a boloko. Empa hlokomela hore matla a kinetic a boloko a tsoa matla a khoheli a ka bang teng. Kahoo ke 'nete hore mosebetsi o etsoa ke matla a khohlano a lekanang le phetoho ea matla a mechini (matla a mechini aa fokotseha).

Karabo e nepahetseng ke C.

5. Ntho e mokatong o bataletseng e otloa kahoo e tsamaea metsotsoana e 3 ebe ea ema. Haeba boima bo tsejoang ba ntho eo e le ligrama tse 10, matla a khohlano pakeng tsa ntho le mokatong ke lik'hilojule tse 2. Fumana mosebetsi o etsoang ke matla a khohlano.

A. 0.18 J

B. -0.18 J

C. 0.36 J

D. -0.36 J

Tse tsejoang:

Nako ea ho arohana (t) = metsotsoana e 3

Lebelo la ho qetela (v _t ) = 0 m/s (phomolo ea ntho)

Boima ba ntho (m) = 10 grams = 10/1000 kg = 1/100 kg = 0.01 kg

Matla a khohlano (F) = 2 kilodynes = 2 x 10 ³ dynes

Ho batloa: Mosebetsi (W) o etsoang ke matla a khohlano

Tharollo:

Phetoho ea li-unit tsa matla:

1 Newton = 1 x 10 ⁵ dyne

Dyne e le 1 = 1 / 10 ⁵ Li-Newton = 1 x 10 ^-5 Li-Newton = 10 ^-5 Li-Newton

Matla a khohlano (F) = 2 x 10 ³ dyne = 2 x 10 ³ x 10 ^-5 Newton = 2 x 10 ^-2 Newton = 2/100 Newton = 0.02 Newton

Mosebetsi oa theorem-matla a mechini a bolela hore mosebetsi o etsoa ke matla a sa bolokeheng nthong e lekanang le phetoho ea matla a mechini a ntho.

Haeba ntho e tsamaya sefofaneng se sekametseng, matla a mechini (ME) = matla a khoheli (PE) + matla a kinetic (KE). Empa haeba ntho e tsamaya feela sefofaneng se otlolohileng kahoo ho se na phetoho bophahamong, matla a mechini = matla a kinetic. Sebakeng se otlolohileng, matla a khoheli ke lefela hobane ha ho na phetoho bophahamong.

Matla a khohlano ke matla a sa bolokeheng. Matla a khohlano hangata a fokotsa lebelo la ntho le matla a kinetic a ntho. A ka etsa qeto ea hore mosebetsi o etsoang ke matla a khohlano nthong o lekana le ho fokotseha ha matla a mechini.

Ka lipalo:

Mosebetsi (W) = Phetoho ea matla a mechini (ΔEM)

F s = ΔEP + ΔEK

F s = mg Δh + ½ m (v _t ² – _vo ² )

F s = mg (0) + ½ m (0 ² – v _o ² )

Fs = 0 + ½ m (– (v _o ² ))

F s = – ½ mv _o ² ———— Tekanyo 1

Tlhaloso: F = matla a khohlano, d = ho falla, m = boima, v _o = lebelo la pele

Ho falla (d) le lebelo la pele (vo _o ) ha li so tsejoe hobane pele bala v _o kapa d. Mosebetsi o etsoang ke matla a khohlano o baloang ho sebelisoa e 'ngoe ea li-equation kamora v _o kapa d e tsejoang.

Tekanyo ea ho falla (d) motsamaong o sa lekanang oa mola o otlolohileng:

v _t ² = v _o ² + 2 (-a) s

Lebelo la ho qetela (v _t ) = 0 mme ho potlakisa (a) ho saennwe ka negative hobane ntho e fokotsehile (lebelo la ntho le fokotsehile).

0 = v_o² – lipapatso tse 2

v_o² = Papatso e 2

d = v _o ² / 2 a ———— Tekanyo ea 2

Phetoho ea d ho equation ea 2 le d ho equation ea 1:

F d = – ½ mv _o ²

F (v _o ² /2a) = – ½ mv _o ²

(F/2a) v _o ² = – ½ mv _o ²

F/2a = – ½ m

F = (2)(a)(-1/2)(m)

F = – (a)(m)

a = – (F / m)

a = – 0.02 Newtons / 0.01 lik'hilograma

a = – 2 Newton/kilogerama

a = – 2 m/s ²

Tekanyo ea ho bala lebelo la pele (v _o ) motsamaong o sa lekanang oa mola o otlolohileng:

v _t = vo _o + ho —–> Lebelo la ho qetela (v _t ) = 0, Ho potlaka (a) = 2 m/s ² , nako e sa fellang (t) = metsotsoana e 3

0 = v _o + (-2)(3)

0 = v _o – 6

v _o = limithara tse 6/motsotsoana

Mosebetsi (W) o etsoang ke matla a khohlano:

W = – ½ mv _o ² = -1/2 (0.01) (6 ² ) = -1/2 (0.01) (36)

W = -1/2 (0.36)

W = – 0.18 Joule

Mosebetsi o etsoang ke matla a khohlano o saennoe ka hore o na le moelelo o fosahetseng, ho bolelang hore mosebetsi o fokotsa matla a mechini a ntho.

Haeba ho tsejoa d, mosebetsi o ka baloa ho sebelisoa equation ea W = F d.

Karabo e nepahetseng ke B.

[ID ea sephutheloana sa wpdm='1178′]

1. Mosebetsi o etsoang ka mathata a matla le litharollo
2. Mathata le litharollo tsa matla a kinetic a mosebetsi
3. Mathata le litharollo tsa motheo oa matla a sebetsang le a mechini
4. Mathata a matla a khoheli le litharollo
5. Matla a ka bang teng a mathata le ditharollo tsa selemo se tenyetsehang
6. Mathata a motlakase le litharollo
7. Tšebeliso ea paballo ea matla a mechini bakeng sa motsamao oa ho oa ka bolokolohi
8. Tšebeliso ea paballo ea matla a mechini bakeng sa motsamao oa holimo le tlase motsamaong oa ho oa ka bolokolohi
9. Tšebeliso ea paballo ea matla a mechini bakeng sa motsamao holim'a bokaholimo bo kobehileng
10. Tšebeliso ea paballo ea matla a mechini bakeng sa motsamao sefofaneng se sekametseng
11. Tšebeliso ea paballo ea matla a mechini bakeng sa motsamao oa liqhomane