fisiks

Tšebeliso ea paballo ea matla a mechini bakeng sa motsamao oa ho oa ka bolokolohi - mathata le litharollo

1. 'Mele oa boima ba 1-kg o oa ka bolokolohi ho tloha phomolong, ho tloha bophahamong ba 80 m. Ho potlaka ka lebaka la matla a khoheli ke 10 m/s ^2.Matla a kinetic ke afe ha 'mele o otla fatše?

Tse tsejoang:

Boima (m) = 1 kg

Bophahamo (h) = 80 m

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

Ho batloa: matla a kinetic ha 'mele o otla fatše

Tharollo:

Matla a pele a mechini (ME _o) = matla a khoheli a ka bang teng (PE)

M E _o= PE = mgh = (1)(10)(80) = 800 Joule

Matla a ho qetela a mechini (M E _t) = matla a kinetic (K E )

Molao-motheo oa paballo ea matla a mechini :

M E _o= M E _t

P E = K E

800 = K E

Matla a ho qetela a kinetic ke 800 Joules.

[irp]

2. 'Mele oa boima ba lik'hilograma tse 4 o oa ka bolokolohi ho tloha phomolong, ho tloha bophahamong ba limithara tse 10. Ho potlaka ka lebaka la matla a khoheli ke 10 ms ^–2 . Matla a kinetic le lebelo la limithara tse 5 ka holim'a lefatše ke eng.

Tse tsejoang:

Phetoho ea bophahamo (h) = 10 – 5 = limithara tse 5 s

Boima (m) = 4 kg

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

Ho batloa: Matla a kinetic a limithara tse 5 ka holim'a lefatše le lebelo la limithara tse 5 ka holim'a lefatše

Tharollo:

(a) Matla a kinetic a limithara tse 5 ka holim'a lefatše

Matla a pele a mechini (M E _o) = matla a khoheli a ka bang teng (P E )

M E _o= PE = mgh = (4)(10)(5) = 200 Joule

Matla a ho qetela a mechini (EM _t) = matla a kinetic (EK)

M E _t= K E

Molao-motheo oa paballo ea matla a mechini o bolela hore matla a pele a mechini = matla a ho qetela a mechini.

M E _o= M E _t

200 = K E

Matla a kinetic a limithara tse 5 ka holim'a lefatše ke 200 Joules.

(b) lebelo la limithara tse 5 ka holim'a lefatše

Matla a pele a mechini (M E _o) = matla a ho qetela a mechini (M E _t)

P E = K E

200 = ½ mv ²

2(200) / 4 = v ²

100 = v ²

v = √100

v = 10 m/s

Lebelo la 'mele ho limithara tse 5 ka holim'a lefatše ke 10 m/s.

[irp]

3. Mango e oa ka bolokolohi ho tloha phomolong, ho tloha bophahamong ba limithara tse 2. Ho potlaka ka lebaka la matla a khoheli ke 10 ms ^–2 . Fumana lebelo la mango ha e fihla fatše.

Tse tsejoang:

Bophahamo (h) = limithara tse 2 s

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

Ho batloa: lebelo la mango ha le fihla fatshe.

Tharollo:

Matla a pele a mechini (M E _o) = matla a khoheli a ka bang teng (P E )

M E = PE = mgh = m (10)(2) = 20 m

Matla a ho qetela a mechini (M E _t) = matla a kinetic (K E )

M E _t= K E = ½ mv ²

Molao-motheo oa paballo ea matla a mechini o bolela hore matla a pele a mechini = matla a ho qetela a mechini.

M E _o= M E _t

20 m = ½ mv ²

20 = ½ v ²

2(20) = ^v2

40 = v ²

v = √40 = √(4)(10) = 2√10 m/ s

[ID ea sephutheloana sa wpdm='1166′]

Bala haholoanyane

Tšebeliso ea paballo ea matla a mechini bakeng sa motsamao o otlolohileng nakong ea ho oa ka bolokolohi - mathata le litharollo

1. Motho o lahlela lejoe la boima ba 1-kg hodimo ka lebelo la 2 m/s ha a ntse a eme moeding wa lefika e le hore lejwe le ka wela botlaaseng ba lefika le dimithara tse 40 ka tlase. Matla a kinetic a lejwe a dimithara tse 10 ka hodima lefatshe ke afe? Ho potlaka ka lebaka la matla a kgoheli g = 10 m/s ².

Tse tsejoang:

Boima (m) = 1 kg

Lebelo la pele (vo _o) = 2 m/s

Phetoho ea bophahamo = 40 - 10 = limithara tse 30

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

Ho batloa: matla a kinetic a lejoe a limithara tse 10 ka holim'a lefatše

Tharollo:

Matla a pele a mechini

Matla a pele a khoheli (EP) = mgh = (1)(10)(30) = 300 Joules

Matla a kinetic a pele (KE) = ½ mv _o² = ½ (1)(2) ² = ½ (4) = 2 Joules

Matla a pele a mechini = matla a pele a khoheli + matla a pele a kinetic = 300 + 2 = 302 Joules.

Matla a ho qetela a mechini

Matla a ho qetela a mechini = matla a ho qetela a kinetic = matla a pele a khoheli + matla a pele a kinetic = 300 + 2 = 302 Joules.

[irp]

2. Motho o lahlela ntho e boima ba 1-kg hodimo moyeng ka lebelo la pele la 10 m/s. Fumana (a) matla a kgoheli a ka bang teng bophahamong bo phahameng ka ho fetisisa (b) bophahamo bo boholo ka ho fetisisa.

Ho potlaka ka lebaka la matla a khoheli ke 10 m/s ²

Tse tsejoang:

Boima (m) = 1 kg

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

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

Ho batloa : matla a khoheli a ka bang teng bophahamong bo phahameng ka ho fetisisa le bophahamong bo phahameng ka ho fetisisa

Tharollo:

(a) matla a khoheli a bophahamo bo phahameng ka ho fetisisa

Matla a pele a mechini:

Matla a pele a mechini (ME) = matla a pele a kinetic (KE) = ½ mv _o² = ½ (1)(10) ² = ½ (100) = 50 Joules.

Matla a ho qetela a mechini:

Matla a ho qetela a mechini (ME) = matla a khoheli a ka bang teng (PE)

Molao-motheo oa paballo ea matla a mechini:

Matla a pele a mechini = matla a ho qetela a mechini

KE = PE

50 = PE

Matla a khoheli a ka bang teng ke 50 Joules.

(b) Bophahamo bo phahameng ka ho fetisisa

PE = mgh

50 = (1)(10) h

50 = lihora tse 10

h = 50 / 10 = limithara tse 5

Bophahamo bo phahameng ka ho fetisisa ke limithara tse 5 ka holimo ho mobu.

[ID ea sephutheloana sa wpdm='1174′]

Bala haholoanyane

Matla a ka bang teng a selemo se tenyetsehang - mathata le ditharollo

1. Boima ba 2-kg bo hoketswe sedibeng. Haeba bolelele ba selemo bo le 4 cm, fumana matla a ka bang teng a selemo se tenyetsehang . Ho potlaka ka lebaka la matla a khoheli ke 10 m/s ².

Tse tsejoang:

Boima (m) = 2 kg

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

Boima (w) = mg = (2)(10) = 20 N

Teleletso (x) = 4 cm = 0.04 m

Ho batloa: Matla a ka bang teng a selemo se tenyetsehang

Tharollo:

Foromo ea molao oa Hooke :

F = kx

F = matla, k = selemo se sa fetoheng, x = phetoho boleleleng ba selemo

Nako e tsitsitseng ea selemo:

k = w / x = 20 / 0.04 = 500 N/m

Matla a ka bang teng a selemo se tenyetsehang:

PE = ½ kx ² = ½ (500) (0.04) ² = (250) (0.0016) = 0.4 Joules

Tharollo e 'ngoe:

PE = ½ kx ² = ½ (bophara / x) x ² = ½ wx = ½ mgx

w = boima, m = boima, x = phetoho boleleleng ba selemo

PE = ½ (2) (10) (0.04) = (10) (0.04) = 0.4 Joules.

[irp]

2. Ho lelefala ha selemo ho otlollotsweng ke matla F = 50 N ke 10 cm. Matla a ka bang teng a selemo se tenyetsehang ke afe haeba ho lelefala ha selemo e le 12 cm.

Tse tsejoang:

Teleletso (x) = 10 cm = 0.1 m

Matla (F) = 50 N

Ho batloa : Matla a ka bang teng a selemo se tenyetsehang

Tharollo:

Nako e tsitsitseng ea selemo:

k = F / x = 50 / 0.1 = 500 N/m

Matla a ka bang teng a selemo se tenyetsehang haeba bolelele ba selemo e le 12 cm. :

PE = ½ kx ² = ½ (500) (0.12) ² = (250) (0.0144) = 3.6 Joules.

[irp]

3. Kerafo ea F khahlanong le x e bontšitsoeng setšoantšong se ka tlase. Matla a ka bang teng a selemo se tenyetsehang ke afe, haeba bolelele ba selemo e le 10 cm.

Matla a ka bang teng a selemo se tenyetsehang - mathata le ditharollo 1

Tse tsejoang:

Matla (F) = 5 N

Ho lelefala ha selemo (x) = 2 cm = 0.02 m

Ho batloa: Matla a ka bang teng a selemo se tenyetsehang haeba bolelele ba selemo e le 0.1 m.

Tharollo:

Nako e tsitsitseng ea selemo:

k = F / x = 5 / 0.02 = 250 N/m

Matla a ka bang teng a selemo se tenyetsehang haeba bolelele ba selemo e le 0.1 m:

PE = ½ kx ² = ½ (250) (0.1) ² = (125) (0.01) = 1.25 Joules.

4. Moatlelete o tlolela hodima seletsa sa selemo se nang le boima ba 500 N, selemo se kgutsufala ka 4 cm. Fumana hore na ke matla a makae a ka qobellang moatlelete.

A. 20 Joule

B. 10 Joule

C. 5 Joule

D. 2 Joule

Tse tsejoang:

Matla (F) = 500 N

Phetoho ea bolelele ba selemo (Δx) = 4 cm = 0.04 m

Ho batloa: Matla a ka bang teng a selemo

Tharollo:

Bala botsitso ba elastic ba selemo o sebedisa equation ya molao wa Hooke:

k = F / Δx = 500 N / 0.04 m = 12500 N/m

Matla a kgonego a ho tenyetseha a selemo:

PE = ½ k Δx ² = ½ (12500) (0.04) ² = (6250) (0.0016)

PE = 10 Joule

Karabo e nepahetseng ke B.

5. Seliba ha se leketlile ka boima ba digrama tse 500, bolelele ba sona bo eketseha ka disentimitara tse 5. Fumana matla a sona a sa fetoheng le a ka bang teng.

Tse tsejoang:

Boima ba ntho (m) = 500 dikgerama = (500/1000) kg = 5/10 kg = 0.5 kg

Ho potlaka (g) = 10 m/s ²

Boima ba ntho (w) = mg = (0.5 kg)(10 m/s ² ) = 5 kg m/s ² = 5 Newtons

Phetoho ea bolelele ba selemo (Δx) = 5 cm = 0.05 m

Ho batloa: matla a sa fetoheng a selemo (k) le a ka bang teng (PE)

Tharollo:

Taba ea pele, bala palo e sa fetoheng ea selemo u sebelisa equation ea molao oa Hooke:

k = w / Δx = 5 N / 0.05 m = 100 N/m

Ho tenyetseha ho ka bang teng ha selemo:

PE = ½ k Δx ² = ½ (100) (0.05) ² = (50) (0.0025)

PE = 0.125 Joule

[ID ea sephutheloana sa wpdm='1179′]

Bala haholoanyane

Matla a khoheli a ka bang teng – mathata le ditharollo

1. Ho wa ha mmele wa boima ba 1 kg ho tloha phomolong, ho tloha bophahamong ba 10 m.

Etsa qeto:

(a) Mosebetsi o etsoang ka matla a khoheli

(b) Phetoho ea matla a khoheli

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

Matla a khoheli a ka bang teng – mathata le ditharollo 1 Tse tsejoang:

Boima (m) = 1 kg

Bolelele (h) = 10 m

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

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

Tharollo:

(a) Mosebetsi o etsoang ka matla a khoheli

W = wh = mgh

W = (1)(10)(10) = 100 Joule

(b) Phetoho ea matla a khoheli

Phetoho ea matla a khoheli e lekana le mosebetsi o etsoang ke matla a khoheli.

Δ EP = 100 Joule

[irp]

2. Ntho ea 10 N e thella fatše holim'a sefofane se sekametseng ka boreledi ho ea ka limithara tse 2. Fumana mosebetsi o entsoeng ka matla a boima!

Matla a khoheli a ka bang teng – mathata le ditharollo 2 Tse tsejoang:

boima (w) = 10 N

w _x= w sebe θ = (10)(sebe 30 ^o ) = (10)(0.5) = 5 N

d = 2 m

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

Ho batloa: mosebetsi o etsoang ke matla a boima

Tharollo:

W = F d = w _x d = (5)(2) = 10 Joule

Tharollo e 'ngoe:

Sebe 30 ^o = h / d

0.5 = lihora / 2

h = (0.5)(2)

h = 1 m

Mosebetsi o etsoang ka matla a boima;

W = F d = wh = (10 N)(1 m) = 10 N m = 10 Joule

[irp]

3. Ntho ea 1,500 gram e bophahamong ba limithara tse 20 ka holim'a lefatše , e oela fatše ka bolokolohi. Matla a khoheli a ntho ke afe? Ho potlaka ka lebaka la matla a khoheli ke 10 m/s ².

Tse tsejoang:

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

Boima (m) = digrama tse 1500 = 1500/1000 dikhilograma = 1.5 dikhilograma

Bophahamo (h) = limithara tse 20

Ho batloa: Matla a khoheli a ka bang teng

Tharollo:

PE = mgh = (1.5 kg)(10 m/s ² )(20 m) = 300 kg m ² /s ² = 300 Joule

4. Ho latela setshwantsho se ka tlase, haeba boima ba ntho ya 1 e le 2 kg mme boima ba ntho ya 2 e le 4 kg, papiso ya matla a ka bang teng a ntho ya 1 le ntho ya 2 ke …..

Tse tsejoang:

Boima ba ntho 1 (m₁) = 2 lik'hilograma Matla a khoheli a ka bang teng – mathata le ditharollo 5

Boima ba ntho 2 (m ₂ ) = 4 lik'hilograma

Bophahamo 1 (lihora tse ₁ ) = limithara tse 12

Bophahamo 2 (lihora tse ₂ ) = limithara tse 9

Ho batloa: Papiso ea matla a ka bang teng a ntho ea 1 le ntho ea 2

Tharollo:

PE = mgh

m = boima (tekanyo ea eona ea machaba ke kilogram, e khutsufalitsoeng kg)

g = ho potlaka ka lebaka la matla a khoheli (yuniti ea eona ea machaba ke limithara ka motsotsoana e sekoere, e khutsufalitsoeng m/s ² )

h = bophahamo (yuniti ea eona ea machaba ke mithara, e khutsufalitsoeng ka m)

PE = matla a khoheli (yuniti ea eona ea machaba ke kg m ² /s ² kapa Joule)

Matla a khoheli a ntho ea 1:

EP ₁ = m ₁ gh ₁ = (2)(g)(12) = 24 g

Matla a khoheli a ntho ea 2:

EP ₂ = m ₂ gh ₂ = (4)(g)(9) = 36 g

Papiso ea matla a ka bang teng a ntho ea 1 le ntho ea 2:

PE ₁ : PE ₂

24 g : 36 g

24: 36

12/24: 12/36

2: 3

[ID ea sephutheloana sa wpdm='1175′]

Bala haholoanyane

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?

Molao-motheo oa matla a mosebetsi le mechine - mathata le litharollo 2

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 _t² – 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 _cd = – μ _kN d = – μ _kwd = – μ _kmgd

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 _t² – v _o² ) = ½ (2) (0 – 10 ² ) = 0 – 100 = -100

Boholo ba ho falla:

W _nc= ΔEK

– 4 s = – 100

s = -100/-4

s = 25 m

[irp]

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: Molao-motheo oa matla a mosebetsi le mechine - mathata le litharollo 3

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 _kN = μ _kw _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 _t² – 60 m

– 32 m = m (1/2 v _t² – 60)

– 32 = 1/2 v _t² – 60

– 32 + 60 = 1/2 v _t²

28 = 1/2 v _t²

2 (28) = v _t²

56 = v _t²

v _t= √4.14

v _t= 2 √14 ms ^-1

[irp]

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: Molao-motheo oa matla a mosebetsi le mechine - mathata le litharollo 5

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 _t² – _vo² )

F s = mg (0) + ½ m (0 ² – v _o² )

Fs = 0 + ½ m (– (v _o² ))

F s = – ½ mv _o² ———— 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 _okapa 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 _t² = v _o² + 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 _o² / 2 a ———— Tekanyo ea 2

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

F d = – ½ mv _o²

F (v _o² /2a) = – ½ mv _o²

(F/2a) v _o² = – ½ mv _o²

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 _o² = -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′]

Bala haholoanyane

Mosebetsi le matla a kinetic - mathata le litharollo

Matla a Kinetic a Mosebetsi :

1. Koloi ea boima ba lik'hilograma tse 5000 e potlakile ho tloha phomolong ho ea ho 20 m/s. Fumana mosebetsi oa letlooa o entsoeng koloing.

Tse tsejoang:

Boima (m) = 5000 kg

Lebelo la pele (vo _o) = 0 m/s ( phomolo ea koloi )

Lebelo la ho qetela (v _t) = 20 m/s

Ho batloa : netweke

Tharollo:

Molao-motheo oa matla a kinetic a mosebetsi :

W _net= Δ EK

Letlooa = ½ m (v _t₂^– v _o² )

W _net= mosebetsi oa net

Δ EK = phetoho ea matla a kinetic

m = boima (kg),

v _t= lebelo la ho qetela (m/s),

v _o= lebelo la pele (m/s).

Marang-rang:

Letlooa = ½ m (v _t₂^– v _o² )

W _nete= ½ (5000)(20 ² – 0 ² )

W _letlooa= (2500)(400 - 0)

W _letlooa= (2500)(400)

W _net= 1000,000 Joule

[irp]

2. Ntho e boima ba 10-kg e potlakisitsoeng ho tloha ho 5 m/s ho isa ho 10 m/s. Fumana mosebetsi o entsoeng ka letlooa holim'a ntho eo!

Tse tsejoang:

Boima (m) = 10 kg

Lebelo la pele (v _o) = 5 m/s

Lebelo la ho qetela (v _t) = 10 m/s

Ho batloa : netweke

Tharollo:

Marang-rang:

W _net= Δ EK

Letlooa = ½ m (v _t₂^– v _o² )

W _nete= ½ (10)(10 ² – 5 ² )

W _letlooa= (5)(100 - 25)

W _letlooa= (5)(75)

W _net= 375 Joule

3. Koloi e boima ba 2000 kg e theoha ka lebelo ho tloha ho 10 m/s ho isa ho 5 m/s. Mosebetsi o etswang koloing ke ofe?

Tse tsejoang:

Boima ba koloi (m) = 2000 kg

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

Lebelo la ho qetela (v _t) = 5 m/s

Ho batloa: netweke

Tharollo:

Marang-rang:

W _net= Δ EK

Letlooa = ½ m (v _t₂^– v _o² )

W _nete= ½ (2000)(5 ² – 10 ² )

W _letlooa= (1000)(25 - 100)

W _net= (1000)(-75)

W _net= -75,000 Joule

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

4. Matla a sa fetoheng a 60-N a sebediswang nthong ya boima ba 10-kg ka metsotswana e 12. Lebelo la pele la ntho ke 6 m/s mme tataiso ya ntho e tshwana le tataiso ya matla.

(1) Mosebetsi o entsoeng nthong eo ke 30,240 Joules

(2) Matla a ho qetela a kinetic ke li-joule tse 30,240

(3) Matla ke 2,520 Watt

(4) Keketseho ea matla a kinetic a ntho ke 180 Joules

Lipolelo tse nepahetseng ke…

Tse tsejoang:

Matla (F) = 60 N

Nako ea ho arohana (t) = metsotsoana e 12

Boima ba ntho (m) = 10 kg

Lebelo la pele (vo _o ) = 6 m/s

Ho batloa: Lipolelo tse nepahetseng

Tharollo:

Ho potlakisa ntho:

∑F = ma

60 = 10 a

a = 60 / 10 = 6 m/s ²

Lebelo la ho qetela:

v _t = v _o + ho

v _t = 6 + (6)(12)

v _t = 6 + 72

v _t = 78 m/s

Sebaka se tsamailoeng ka metsotsoana e 12:

s = vo _o t + 1/2 ho ²

s = (6)(12) + 1/2 (6)(12) ²

s = 72 + (3)(144)

s = 72 + 432

s = limithara tse 504

(1) Mosebetsi o etsoang ka likhoka

W = F s = (60)(504) = 30,240 Joule

(2) Matla a ho qetela a kinetic

KE = 1/2 mv _t² = 1/2 (10) (78) ² = (5) (6084) = 30,420 Joules

(3) Matla

P = W / t = 30,240 / 12 = 2,520 Joules/motsotsoana

(4) Keketseho ea matla a kinetic

ΔKE = 1/2 mv _t² – 1/2 mv _o² = 1/2 m (v _t² – v _o² ) = 1/2 (10) (78 ² – 6 ² ) = 5 (6084 –36) = 5 (6048)

ΔKE = 30,240 Joule

[irp]

5. Mosebetsi o moholo o etsoa ka nomoro ea ntho…

Matla a kinetic - mathata le litharollo 1

Tharollo:

Mosebetsi oa netweke = phetoho ea matla a kinetic

Letlooa = ½ m (v _t₂^– v _o² )

Mosebetsi o moholo:

W ₁ = ½ (8)(4 ² – 2 ² ) = (4)(16 – 4) = (4)(12) = 48 Dijoule

W ₂ = ½ (8)(5 ² –3 ² ) = (4)(25 – 9) = (4)(16) = 64 Joule

W ₃ = ½ (10)(6 ² – 5 ² ) = (5)(36 – 25) = (5)(11) = 55 Dijoule

W ₄ = ½ (10)(4 ² – 0 ² ) = (5)(16 – 0) = (5)(16) = 80 Dijoule

W ₅ = ½ (20)(3 ² – 3 ² ) = (10)(9 – 9) = (10)(0) = 0 Dijoule

6. Koloi ea boima ba 4000 kg e tsamaea moleng o otlolohileng ka lebelo la 25 m/s. Koloi e fokotsoa hore lebelo la ho qetela la koloi e be 15 m/s. Mosebetsi o etsoang koloing ke ofe?

Tse tsejoang:

Boima (m) = 4000 kg

Lebelo la pele (vo _o ) = 25 m/s

Lebelo la ho qetela (v _t ) = 15 m/s

Ho batloa : Mosebetsi o entsoeng koloing

Tharollo:

W _net = ½ m (v _t² – vo ₂⁾ = ½(4000)(15 ² -25 ² ) = (2000)(225-625) = (2000)(-400) = -800,000 Lijoule = -800 kJ

[irp]

7. 0.1-kg e lahleloang ka ho otloloha ho 6 m/s ho tloha bophahamong ba limithara tse 5. Haeba ho potlaka ha matla a khoheli e le 10 m/s ² , joale matla a kinetic a bolo bophahamong ba limithara tse 2 ke afe.

Tse tsejoang: Matla a kinetic - mathata le litharollo 2

Boima (m) = 0.1 kg

Phetoho ea bophahamo (h) = 5 m - 2 m = 3 metres

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

Ho batloa: Matla a kinetic a bophahamo ba limithara tse 2.

Tharollo:

Motsamao o otlolohileng o ka utloisisoa ka ho sekaseka likarolo tse otlolohileng le tse otlolohileng tsa motsamao ka thoko. Motsamao o shebileng ka ho rapama o sekasekoa e le motsamao o sa fetoheng oa lebelo le motsamao o shebileng ka ho rapama o sekasekoa e le motsamao oa ho oa ka bolokolohi kapa motsamao o otlolohileng.

Matla a pele a mechini = matla a khoheli a ka bang teng.

PE = mgh = (0.1)(10)(3) = 3 Joule.

Matla a ho qetela a mechini = matla a kinetic.

KE = 3 Joule.

8. Koloi ea boima ba lik'hilograma tse 1000 e potlakisa ho tloha phomolong 'me e tsamaea ka lebelo la 5 m/s. Mosebetsi o etsoang ke koloi ke ofe?

Tse tsejoang:

Boima (m) = 1000 kg

Lebelo la pele (v _o ) = 0

Lebelo la ho qetela (v _t ) = 5 m/s

Ho batloa: Mosebetsi (W) o etsoang ka koloi

Tharollo:

Letlooa = ½ m (v _t₂^– v _o² )

Mosebetsi o etsoang ka koloi:

W _net = ½ (1000)(5 ² – 0 ² ) = (500)(25 – 0) = (500)(25) = 12,500 Joule

[irp]

9. Bolo ea ligrama tse 500 e lahleloa holimo holimo ho tloha holim'a lefatše ka lebelo la pele la 10 m/s ² . Ho potlaka ka lebaka la matla a khoheli ke 10 ms ^-2 . Mosebetsi o etsoang ke matla a boima ke ofe ha bolo e fihla bophahamong bo phahameng ka ho fetisisa?

Tse tsejoang :

Boima ba bolo (m) = 500 grams = 0.5 kg

Lebelo la pele (v _o ) = 10 m/s ²

Lebelo la ho qetela (v _t ) = 0 (lebelo ntlheng e phahameng ka ho fetisisa)

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

Ho batloa: Mosebetsi (W) o etsoa ka boima

Tharollo:

Mosebetsi oa letlooa o etsoang ke matla a letlooa nthong = phetoho ea matla a kinetic.

W _net = ΔEK = EK _t – EK _o

Letlooa = ½ mv _t² – ½ mv _o² = ½ m (v _t² – v _o² )

KE _t = matla a ho qetela a kinetic, KE _o = matla a pele a kinetic, m = boima ba ntho, v _t = lebelo la ho qetela la ntho, v _o = lebelo la pele la ntho.

Marang-rang:

W _nete = ½ m (v _t² – v _o² ) = ½ (0.5)(0 ² – 10 ² )

W _net = (0.25)(-100) = -25 Joule

Letšoao la ho tlosa le bontša hore tsela eo bolo e tsamaeang ka eona e fapane le boima ba eona. Tsela eo bolo e tsamaeang ka eona e otlolohile 'me tsela eo boima bo tsamaeang ka eona e otlolohile.

10. Ntho e boima ba 1-kg e oa ka bolokolohi ka phapang ea bophahamo = limithara tse 2.5. Ho potlaka ka lebaka la matla a khoheli ke 10 ms ^-2 . Mosebetsi o etsoang nthong eo ke ofe?

Tse tsejoang:

Boima ba bolo (m) = 1 kg

Lebelo la pele (vo _o ) = 0 m/s

Bophahamo (h) = limithara tse 2.5

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

Ho batloa: Mosebetsi oa inthanete nakong ea ho falla

Tharollo:

Lebelo la ho qetela la bolo (v _t )

Ho baloa ho sebelisoa equation ea motsamao oa ho oa ka bolokolohi. Tse tsejoang: Ho potlaka ka lebaka la matla a khoheli (g) = 10 m/s ² , Phetoho ea bophahamo ba bolo (h) = limithara tse 2.5. Ho batloa: Lebelo la ho qetela.

v _t² = 2 gh = 2(10)(2.5) = 2(25)

v _t = √2(25)

v _t = 5√2

Mosebetsi oa netweke = phetoho ea matla a kinetic

W _nete = ΔEK = ½ m (v _t² – v _o² ) = ½ (1){(5√2) ² – 0 ² }

W _net = ½ (25)(2) = 25 Joule

[irp]

11. Ntho e boima ba 2 kg e tsamaya ka lebelo la 72 km/hora. Kamora ho tsamaya dimithara tse 400, lebelo la ho qetela la ntho ke 144 km/hora. Ho potlaka ka lebaka la matla a khoheli ke 10 ms ^-2 . Fumana mosebetsi wa netweke.

Tse tsejoang:

Boima ba ntho (m) = 2 kg

Lebelo la pele (v _o ) = 72 km/hora = 20 m/s

Lebelo la ho qetela (v _t ) = 144 km/h = 40 m/s

Sebaka (li) = limithara tse 400

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

Ho batloa: Marang-rang

Tharollo:

Mosebetsi oa netweke = liphetoho tsa matla a kinetic

W _nete = ΔEK = ½ m (v _t² – v _o² ) = ½ (2) (40 ² – 20 ² }

W _net = ½ (2)(1600 - 400) = 1200 Joule

12. Ntho e boima ba 2-kg e tsamaya ka 2 ms ^–1 . Mosebetsi o etswang nthong ke 21 Joules. Lebelo la ho qetela la ntho ke lefe.

Tse tsejoang:

Boima (m) = 2 kg

Lebelo la pele (vo _o ) = 2 m/s

Mosebetsi (W) = 21 Joule

Ho batloa: lebelo la ho qetela (v _t )

Tharollo:

W _net = ΔEK

W _net = 1/2 mv _t² -1/2 mv _o²

Letlooa = 1/2 m (v _t²_– v _o² )

21 = 1/2 (2) (v _t² – 2 ² )

21 = (v _t² – 2 ² )

21 = v _t² – 4

v _t² = 21 + 4 = 25

v _t = √25

v _t = 5 m/s

[irp]

1 3. Matla a sa fetoheng a 8 N a sebetsa nthong e boima ba 16 kg. Haeba ntho e phomotse qalong, joale fumana lebelo la ntho ka mor'a hore matla a sebetse nthong metsotsoana e 4.

Tse tsejoang:

Matla a sa fetoheng (F) = 8 Newton

Boima ba ntho (m) = 16 kg

Lebelo la pele la ntho (vo _o) = 0 m/s

Nako ea nako ea matla e sebetsa nthong (t) = metsotsoana e 4

Ho batloa: Lebelo la ho qetela (v _t )

Tharollo:

Mosebetsi = Phetoho ea matla a kinetic

W = KE ea ho qetela – KE ea pele

W = ½ mv _t² – ½ mv _o²

W = ½ mv _t² – 0

W = ½ mv _t² —— Tekanyo 1

Mosebetsi = Matla x Ho falla

W = F d

W = 8 d

Sebelisa equation ea motsamao o sa lekanang oa mola o ka tlase ho bala ho falla (d):

d = vo _ot + ½ ho ²

d = ho falla, v _o= lebelo la pele, t = nako e sa fellang, a = ho potlaka

d = 0 + ½ ho ² = ½ ho ² —-> a = (v _t– vo _o) / t = v _t/ t

d = ½ (v _t/ t) t ²

^d = ½ (v _t) t

Phetoho ea ho falla (d) ho equation ea Sebetsa le ho falla (d) ho equation ena:

W = 8 d

W = 8(1/2)(v _t)(t)

W = (4)(v _t)(t) —— equation 2

Tekanyo ea 1 = Tekanyo ea 2

W = W

½ mv _t² = (4)(v _t)(t)

½ mv _t= (4)(t)

½ (16)(v _t) = 4(4)

8 v _t= 16

v _t= 16 / 8

v _t= limithara tse 2/motsotsoana

14. Ho eketsa lebelo la ntho e fetohang makhetlo a 2 ho feta lebelo la pele, fumana mosebetsi o hlokahalang ts'ebetsong…

Tse tsejoang:

Boima ba ntho (m) = 1 kg

Lebelo la pele (vo _o) = 1 m/s

Lebelo la ho qetela (v _t) = 2 x lebelo la pele = 2 x 1 = 2 m/s

Ho batloa: Mosebetsi

Tharollo:

Matla a pele a kinetic:

KE qalong = ½ mv _o² = ½ (1) (1) ² = ½ (1) (1) = ½ (1) = 0.5

Matla a ho qetela a kinetic ha lebelo la ntho le fetoha makhetlo a 2 a lebelo la eona la pele:

HO ea ho qetela = ½ mv _t² = ½ (1)(2) ² = ½ (4) = 2

Khopolo-taba ea matla a sebetsang le a kinetic:

Mosebetsi = Phetoho ea matla a kinetic

Mosebetsi = Matla a ho qetela a kinetic – matla a pele a kinetic

Mosebetsi = 2 – 0.5

Mosebetsi = 1.5

Matla a kinetic a pele = 0.5

Mosebetsi = 3 x 0.5 = 1.5

Mosebetsi o hlokahalang ka makhetlo a 3 a matla a eona a kinetic a pele.

15. Koloi e boima ba 1500 kg e tsamaya ka lebelo la 36 km/hora tseleng e otlolohileng le e boreleli e otlolohileng. Koloi e potlakile ho fihla ho 72 km/hora. Fumana mosebetsi o hlokahalang ho potlakisa koloi.

Tse tsejoang:

Boima ba koloi (m) = 1500 kg

Lebelo la pele la koloi (v _o) = 36 km/hora = 36,000 metres / 3600 metsotsoana = 10 metres/motsotsoana

Lebelo la ho qetela la koloi (v _t) = 72 km/hora = 72,000 metres / 3600 metsotsoana = 20 metres/motsotsoana

Ho batloa: Ho hlokahala mosebetsi ho potlakisa koloi

Tharollo:

Khopolo-taba ea matla a sebetsang le a kinetic:

W = EK final – EK initial

W = ½ mv _t² – ½ mv _o² = ½ m (v _t² –v _o² )

W = ½ (1500)(20 ² - 10 ² )

W = ½ (1500)(400 - 100)

W = ½ (1500)(300)

W = (1500)(150)

W = 225,000 Joule

16. Ntho e boima ba 2 kg e qala ka lebelo la 72 km. hora ^-1 . Kamora ho tsamaya tseleng e otlolohileng e otlolohileng ho fihlela ho 400 m, lebelo la ntho ke 144 km. hora ^-1 . Fumana kakaretso ea mosebetsi holim'a ntho eo.

Tse tsejoang:

Boima ba ntho (m) = 2 kg

Lebelo la pele (v _o) = 72 km/hora = limithara tse 72,000 / metsotsoana e 3600 = 20 m/s

Lebelo la ho qetela (v _t) = 144 km/hora = 144,000 metres / metsotsoana e 3600 = 40 m/s

Sebaka sa ntho = limithara tse 400

Ho batloa: Mosebetsi oa inthanete nthong eo

Tharollo:

Khopolo-taba ea matla a kinetic a mosebetsi e bolela hore mosebetsi oa netweke o sebetsa nthong ka tsela e tšoanang le phetoho ea matla a kinetic a ntho.

W net = HO ea ho qetela – HO ea qalong

W net = ½ mv _t² – ½ mv _o²

Letlooa = ½ m (v _t² – v _o² )

W nete = ½ (2) (40 ² – 20 ² )

W letlooa = 1600 – 400

W net = 1200 Joule

Tlhaloso:

W = Mosebetsi, KE = matla a kinetic

Matla a kinetic

17. Kulo ea ligrama tse 10 e tsamaeang ka lebelo le sa fetoheng la 100 m/s. Matla a kinetic a kulo ke afe?

Tse tsejoang:

Boima ba kulo (m) = 10 grams = 10/1000 lik'hilograma = 1/100 lik'hilograma = 0.01 lik'hilograma

Lebelo la kulo (v) = limithara tse 100/motsotsoana

Ho batloa: Matla a kinetic

Tharollo:

KE = 1/2 mv ²

KE = 1/2 (0,01 kg)(100 m/s) ²

KE = 1/2 (0,01 kg)(10.000 m ² /s ² )

KE = (0,01 kg)(5000 m ² /s ² )

KE = 50 kg m ² /s ²

KE = 50 Joule

[ID ea sephutheloana sa wpdm='1191′]

Bala haholoanyane

Mosebetsi o etsoang ka likhoka - mathata le litharollo

1. Motho o hula boloko bo bolelele ba limithara tse 2 holim'a bokaholimo bo bataletseng ka matla a sa fetoheng F = 20 N. Fumana mosebetsi o entsoeng ka matla F o sebetsang holim'a boloko.

Mosebetsi o etsoang ka likhoka - mathata le litharollo 1

Tse tsejoang:

Matla (F) = 20 N

Sebaka (s) sa ho falla = 2 m

Sekhutlo (θ ) = 0

Ho Batloa : Mosebetsi (W)

Tharollo:

W = F d cos θ = (20)(2)(cos 0) = (20)(2)(1) = 40 Joules

[irp]

2. Matla F = 10 N a sebetsang lebokoseng la 1 m hodima bokaholimo bo otlolohileng. Matla a sebetsa ka sekhutlo sa 30 ^o jwalo ka ha ho bontshitswe setshwantshong se ka tlase. Fumana mosebetsi o etswang ka matla F!

Mosebetsi o etsoang ka likhoka - mathata le litharollo 2

Tse tsejoang :

Matla (F) = 10 N

Matla a rapameng (F _x) = F cos 30 ^o = (10)(0.5√3) = 5√3 N

Ho falla (d) = mithara e le 1

Ho Batloa : Mosebetsi (W)?

Tharollo :

W = F _xd = (5√3)(1) = 5√3 Li-joule

3. 'Mele o oa ka bolokolohi phomolong, ho tloha bophahamong ba limithara tse 2. Haeba lebelo le bakoang ke matla a khoheli e le 10 m/s ^, fumana mosebetsi o etsoang ke matla a khoheli!

Tse tsejoang:

Boima ba ntho (m) = 1 kg

Bolelele (h) = 2 m

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

Ho batloa: Mosebetsi o entsoeng ka matla a khoheli (W)

Tharollo:

W = F d = wh = mgh

W = (1)(10)(2) = 20 Joule

W = mosebetsi, F = matla, d = sebaka, w = boima , h = bophahamo, m = boima, g = ho potlaka ka lebaka la matla a khoheli.

[irp]

4. Ntho e boima ba 1-kg e hoketswe sedibeng kahoo e lelefatswa ka 2 cm. Haeba lebelo le bakwang ke matla a kgoheli e le 10 m/s ² , fumana (a) botsitso ba selemo (b) mosebetsi o etswang ke matla a selemo nthong eo

Tse tsejoang:

Boima (m) = 1 kg

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

Teleletso (x) = 2 cm = 0.02 m

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

Ho batloa: Nako e tsitsitseng ea selemo le mosebetsi o etsoang ke matla a selemo

Tharollo:

(a) Sephetho sa selemo

Foromo ea molao oa Hooke :

F = k x.

k = F / x = w / x = mg / x

k = (1)(10) / 0.02 = 10 / 0.02

k = 500 N/m

(b) mosebetsi o etsoang ke matla a selemo

W = – ½ kx ²

W = – ½ (500)(0.02) ²

W = – (250)(0.0004)

W = -0.1 Joule

Letšoao la ho tlosa le bontša hore tataiso ea matla a selemo e fapane le tataiso ea ho falla ha ntho.

[irp]

5. Matla F = 10 N a potlakisa lebokose holim'a ho falla ha 2 m. Fatše le khopame 'me le na le matla a khohlano F _k= 2 N. Fumana mosebetsi oa letlooa o entsoeng lebokoseng.

Mosebetsi o etsoang ka likhoka - mathata le litharollo 3

Tse tsejoang:

Matla (F) = 10 N

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

Ho falla (d) = 2 m

Ho batloa: Marang-rang (W _net)

Tharollo:

Mosebetsi o etsoang ka matla F:

W ₁= F d cos 0 = (10)(2)(1) = 20 Joule

Mosebetsi o etsoang ka matla a moferefere oa kinetic (F _k):

W ₂= F _kd = (2)(2)(cos 180) = (2)(2)(-1) = -4 Dijoule

Marang-rang:

W _letlooa= W ₁– W ₂

W _letlooa= 20 – 4

W _net= 16 Joule

6. Mosebetsi o etsoang ka matla F bolokong ke ofe?

Tse tsejoang: Mosebetsi o etsoang ka likhoka - mathata le litharollo 1

Matla (F) = 12 Newton

Ho falla (d) = limithara tse 4

Ho Batloa: Mosebetsi (W)

Tharollo:

W = F d = (12 Newton)(limithara tse 4) = 48 N m = 48 Joule

[irp]

7. Boloko bo sutumelletsoa ke matla a 200 N. Ho falla ha boloko ke limithara tse 2. Mosebetsi o etsoang bolokong ke ofe?

Tse tsejoang:

Matla (F) = 200 Newton

Ho falla (d) = limithara tse 2

Ho Batloa: Mosebetsi (W)

Tharollo:

Mosebetsi:

W = F s

W = (200 Newton)(limithara tse 2)

Bophahamo = 400 N m

W = 400 Joule

8. Mokhanni oa sedan o batla ho paka koloi ea hae hantle 0.5 m ka pel'a teraka e leng 10 m ho tloha moo sedan e leng teng. Mosebetsi o hlokoa ke ofe ke oa sedan?

Tse tsejoang: Mosebetsi o etsoang ka likhoka - mathata le litharollo 2

Ho falla (d) = limithara tse 10 – limithara tse 0.5 = limithara tse 9.5

Matla (F) = 50 Newton

Ho Batloa: Mosebetsi (W)

Tharollo:

W = F s

W = (50 Newton)(limithara tse 9.5)

Bophahamo = 475 N m

W = 475 Joule

[irp]

Mosebetsi o etsoang ka likhoka - mathata le litharollo 3

Mosebetsi o entsoeng ke Tom le Jerry e le hore koloi e ka tsamaea ho fihlela ho limithara tse 4. Matla a sebelisoang ke Tom le Jerry ke 50 N le 70 N.

Tse tsejoang:

Ho falla (ma) = limithara tse 4

Matla a letlooa (F) = 50 Newtons + 70 Newtons = 120 Newtons

Ho Batloa: Mosebetsi (W)

Tharollo:

W = F s = (120 Newton)(limithara tse 4) = 480 N m = 480 Joule

10. Mokhanni o hula koloi hore koloi e tsamaee ho fihlela ho 1000 cm. Mosebetsi o etsoa koloing ke ofe?

Tse tsejoang: Mosebetsi o etsoang ka likhoka - mathata le litharollo 4

Matla (F) = 250 Newton

Sebaka (ma) sa ho falla = 1000 cm = 1000/100 metres = 10 metres

Ho Batloa: Mosebetsi (W)

Tharollo:

W = F s = (250 Newton)(limithara tse 10) = 2500 N m = 2500 Joule

11. Ho latela setšoantšo se ka tlase, haeba mosebetsi o etsoang ka matla a letlooa e le 375 Joules, fumana ho falla ha ntho.

Mosebetsi o etsoang ka likhoka - mathata le litharollo 11

Tse tsejoang:

Mosebetsi (W) = 375 Joule

Matla a marang-rang ( ΣF) = 40 N + 10 N – 25 N = 25 Newtons ( ka ho le letona )

Ho Batloa: Ho falla ( d )

Tharollo:

Tekanyo ea mosebetsi:

W = F s

Ho falla ha ntho:

d = W / F = 375 Joule / 25 Newtons

d = limithara tse 15 s

12. Mesebetsi e ka tlase e sa sebetseng ke …

A. Sututsa ntho ho fihlela ho dimithara tse 10

B. Sututsa koloi ho fihlela e tsamaea

C. Sututsa lebota

D. Ke hutse lebokose

Tharollo:

Tekanyo ea mosebetsi:

W = ΣF s

W = mosebetsi , F = matla , d = ho falla

Ho latela foromo e ka holimo, mosebetsi o etsoa ka matla 'me ho na le ho falla.

Karabo e nepahetseng ke C.

1 3. Andrew o sututsa ntho ka matla a 20 N kahoo ntho e tsamaya ka motsamao o chitja ka radius ya dimithara tse 7. Fumana mosebetsi o entsweng ke Andrew bakeng sa motsamao o chitja o makgetlo a mabedi.

A. 0 Joule

B. 1400 Joule

C. 1540 Joule

D. 1760 Joule

Tharollo:

Haeba motho a sututsa setulo sa likooa ka motsamao o chitja habeli, motho eo le setulo sa likooa ba khutlela boemong ba bona ba pele, kahoo ho falla ha motho eo ke lefela.

Ho falla = 0 kahoo mosebetsi = 0.

Karabo e nepahetseng ke A.

14. Motho e mong o sutumelletsa ntho fatše ka matla a 350 N. Fatše le na le matla a khohlano a 70 N. Fumana mosebetsi o etsoang ka matla ho tsamaisa ntho ho fihlela limithara tse 6.

A. 45 J

B. 72 J

C. 1680 J

D. 2580 J

Tse tsejoang:

Matla a ho sututsa (F) = 350 Newtons

Matla a khohlano (F _fric) = 70 Newtons

Ho falla ha ntho (lintho) = limithara tse 6

Ho Batloa: Mosebetsi (W)

Tharollo:

Ho na le matla a mabeli a sebetsang nthong, matla a sutumetsang (F) le matla a khohlano (F _fric). Matla a sutumetsang a na le tataiso e tšoanang le ho falla ha ntho hobane matla a sutumetsang a etsa mosebetsi o motle. Ka lehlakoreng le leng, matla a khohlano a na le tataiso e fapaneng le ho falla ha ntho hoo matla a khohlano a etsang mosebetsi o mobe.

Mosebetsi o etsoang ka matla a ho sutumelletsa:

W = F d = (350 Newton)(limithara tse 6) = 2100 Limithara tsa Newton = 2100 Joule

Mosebetsi o etsoang ka matla a khohlano:

W = – (F _fric)(s) = – (70 Newton)(limithara tse 6) = – 420 Newton-meters = – 420 Joule

Marangrang:

W net = 2100 Joule – 420 Joule

W net = 1680 Joule

Karabo e nepahetseng ke C.

15. Ntho e sutumelletsoa ke matla a bataletseng a li-Newton tse 14 mokatong o bataletseng ka matla a khohlano a li-Newton tse 10. Fumana mosebetsi oa letlooa oa ho tsamaisa ntho ho fihlela limithara tse 8.

A. 0.5 Joule

B. 3 Joule

C. 32 Joule

D. 192 Joule

Tse tsejoang:

Matla a sutumetsang (F) = 14 Newton

Matla a khohlano (F _fric) = 10 Newtons

Ho falla ha ntho (d) = limithara tse 8

Ho Batloa: Mosebetsi (W)

Tharollo:

Ho na le matla a mabeli a sebetsang nthong, matla a sutumetsang (F) le matla a khohlano (F _fric).

Matla a sututsang a na le tataiso e tšoanang le ho falla ha ntho e le hore matla a sututsang a etse mosebetsi o motle. Ka lehlakoreng le leng, matla a khohlano a na le tataiso e fapaneng le ho falla ha ntho e le hore matla a khohlano a etse mosebetsi o mobe.

Mosebetsi o etsoang ka matla a ho sutumelletsa:

W = F s = (14 Newton)(limithara tse 8) = 112 Limithara tsa Newton = 112 Lijoule

Mosebetsi o etsoang ka matla a khohlano:

W = – (F _fric)(s) = – (10 Newton)(limithara tse 8) = – 80 Limithara tsa Newton = – 80 Lijoule

Marangrang:

W net = 112 Joule – 80 Joule

W net = 32 Joule

Karabo e nepahetseng ke C.

16. Fumana mosebetsi oa netweke ho latela setšoantšo se ka tlase.

A. 360 Joule Sebetsa

B. 450 Joule

C. 600 Joule

D. 750 Joule

Tharollo:

Mosebetsi = Matla (F) x ho falla (d)

Mosebetsi = Sebaka sa khutlotharo 1 + sebaka sa khutlotharo + sebaka sa khutlotharo 2

Work = 1/2(40-0)(3-0) + (40-0)(9-3) + 1/2(40-0)(12-9)

Mosebetsi = 1/2(40)(3) + (40)(6) + 1/2(40)(3)

Mosebetsi = (20)(3) + 240 + (20)(3)

Mosebetsi = 60 + 240 + 60

Mosebetsi = 360 Joule

Karabo e nepahetseng ke A.

17. Sekotwana sa patsi se bolelele ba 60 cm se kentswe mobung ka ho otloloha. Patsi e otlwa ka hamore ya 10-kg ho tloha bophahamong ba 40 cm hodimo ho patsi. Haeba matla a mahareng a khanyetso ya lefatshe e le 2 x 10 3 ^N mme lebelo le bakwang ke matla a kgoheli e le 10 m/s ² , patsi e tla kena mobung ka botlalo kamora ho… otla.

A. 4

B. 16

C. 28

D. 30

Tse tsejoang:

Boima ba hamore (m) = 10 kg

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

Boima ba hamore (w) = mg = (10)(10) = 100 kg m/s ²

Ho tlosa hamore pele e otla patsi (d) = 40 cm = 0.4 metres

Khanyetso ea lehong (F) = 2 x 10 ³ N = 2000 N

Bolelele ba patsi = 60 cm = 0.6 metres

Ho batloa: Patsi e tla kena ka botlalo mobung kamora ho… otla.

Tharollo:

Mosebetsi o entsoeng holim'a hamore ha hamore e tsamaea ho fihlela ho limithara tse 0.4 ke:

W = F d = ws = (100 N)(0.4 m) = 40 Nm = 40 Joule

Mosebetsi o etsoang ke matla a khanyetso a lefats'e:

W = F d = (2000 N)(0.6 m) = 1200 Nm = 1200 Joule

Patsi e tla kena ka botlalo mobung kamora… ho otloa.

Lijoule tse 1200 / Lijoule tse 40 = 30

Karabo e nepahetseng ke D.

[ID ea sephutheloana sa wpdm='1192′]

Bala haholoanyane

Molao oa Kepler - mathata le litharollo

1. Sebaka sa Lefatše ho tloha Letsatsing ke 149.6 x 10 ⁶ km mme nako ya phetoho ya Lefatshe ke selemo se le seng. Bala T ² / r ³

Tse tsejoang:

T = selemo se le seng, r = 149.6 x 10 ⁶ km

Ho batloa : T ² / r ³ = … ?

Tharollo :

k = T² /r³= 1² / (149.6 x 10⁶)³ = 1 / (3348071.9 x 10¹⁸) = 2.98 x 10^-25selemo²/ km³

[irp]

2. Sephetho sa bokahohleng (G) = 6.67 x 10 ^-11 Nm ² /kg ² le Sun's 1.99 x 10 ³⁰ kg.

Molao oa Kepler – mathata le litharollo 2

[irp]

3. Sebaka se mahareng sa Lefatše ho tloha Letsatsing ke 149.6 x 10 ⁶ km mme sebaka se mahareng sa Mercury ho tloha Letsatsing ke 57.9 x 10 ⁶ km. Nako ea phetoho ea Lefatše ke selemo se le seng, nako ea phetoho ea Mercury ke efe?

Tse tsejoang:

r ea Lefatše = 149.6 x 10 ⁶ km

r ea mercury = 57.9 x 10 ⁶ km

T ea Lefatše = selemo se le seng

Ho batloa: T ea mercury?

Tharollo:

Molao oa Kepler – mathata le litharollo 3

[ID ea sephutheloana sa wpdm='953′]

Bala haholoanyane

Sathelaete ea Geosynchronous - mathata le litharollo

1. Bophahamo ba sathelaete e tsamaisanang le geosynchronous ka hodima bokahodimo ba Lefatshe ke bofe?

G = boleng bo sa fetoheng ba bokahohle = 6.67 x 10 ^-11 N m ² /kg ²

M = Boima ba Lefatše = 5.97 x 10 ²⁴ kg

T = lihora tse 24 = 24 (metsotsoana e 3600) = metsotsoana e 86,400 = 8.64 x 10 metsotsoana ^{e 4}

tharollo

Sathelaete ea Geosynchronous - mathata le litharollo 1

Bophahamo ba sathelaete ka holim'a bokaholimo ba Lefatše = 4.22 x 10 ⁷ m = 4.22 x 10 ⁴ km = 42,200 km

Bophahamo ba sathelaete ka holim'a bokaholimo ba Lefatše = 6.38 x 10 ⁶ m = 6.38 x 10 ³ km = 6380 km

Bophahamo ba sathelaete ka holim'a bokaholimo ba Lefatše = sebaka sa sathelaete ho tloha bohareng ba Lefatše - radius ea Lefatše

Bophahamo ba sathelaete ka holim'a bokaholimo ba Lefatše = 42,200 km - 6380 km

Bophahamo ba sathelaete ka holim'a bokaholimo ba Lefatše = 35,820 km

[irp]

2. Lebelo la sathelaete e tsamaisanang le jeosynchronous ke lefe?

Sephetho sa bokahohleng (G) = 6.67 x 10 ^-11 N m ² /kg ²

Boima ba Lefatše (m _E) = 5.97 x 10 ²⁴ kg

Sebaka se pakeng tsa sathelaete le setsi sa Lefatše (r) = 4.22 x 10 ⁷ m

tharollo

Sathelaete ea Geosynchronous - mathata le litharollo 2

kapa sebelisa equation ena

Sathelaete ea Geosynchronous - mathata le litharollo 3

[ID ea sephutheloana sa wpdm='949′]

Bala haholoanyane

Molao oa Newton oa matla a khoheli a bokahohleng - mathata le litharollo

1. Sebaka se pakeng tsa motho ea boima ba lik'hilograma tse 40 le motho ea boima ba lik'hilograma tse 30 ke limithara tse 2. Matla a khoheli ao e mong le e mong a a sebelisang ho e mong ke afe. Bokahohle bo sa fetoheng = 6.67 x 10 ^-11 N m ² / kg ²

Tse tsejoang:

m ₁= 40 kg, m ₂= 30 kg, r = 2 m, G = 6.67 x 10 ^-11 N m ² / kg ²

Ho batloa: boholo ba matla a khoheli (F)?

Tharollo:

Molao oa Newton oa matla a khoheli a bokahohleng - mathata le litharollo 1

[irp]

2. Sebaka se pakeng tsa Lefatše le Khoeli (r) ke 3.84 x 10 ⁸ m. Matla a khoheli ao e 'ngoe le e 'ngoe e a sebelisang ho e 'ngoe ke afe?

Tse tsejoang:

Boima ba Lefatše (m _E) = 5.97 x 10 ²⁴ kg

Boima ba Khoeli (m _M) = 7.35 x 10 ²² kg

Sebaka se pakeng tsa setsi sa Lefatše le setsi sa Khoeli (r) = 3.84 x 10 ⁸ m

Sephetho sa bokahohleng (G) = 6.67 x 10 ^-11 N m ² / kg ²

Ho batloa: Boholo ba matla a khoheli (F)

Tharollo:

Molao oa Newton oa matla a khoheli a bokahohleng - mathata le litharollo 2

[irp]

3. Sebaka se hokae ho tloha Lefatšeng, boholo ba matla a khoheli a lefatše le khoeli ke lefela?

Tse tsejoang:

Boima ba Lefatše = 5.97 x 10 ²⁴ kg

Boima ba Khoeli = 7.35 x ¹⁰²² kg

Sebaka se pakeng tsa setsi sa Lefatše le setsi sa Khoeli (r) = 3.84 x 10 ⁸ m.

Sephetho sa bokahohleng ( G) = 6.67 x 10 ^-11 N m ² / kg ²

Ho batloa: sebaka ho tloha Lefatšeng

Tharollo:

Molao oa Newton oa matla a khoheli a bokahohleng - mathata le litharollo 3

Matla a khoheli a net ke lefela.

Molao oa Newton oa matla a khoheli a bokahohleng - mathata le litharollo 4

Sebelisa foromo ea quadratic:

A = – 6.35

B = – 7.68 x 10 ⁸

C = 87.76 x 10 ^-14

Molao oa Newton oa matla a khoheli a bokahohleng - mathata le litharollo 5

[ID ea sephutheloana sa wpdm='955′]

Bala haholoanyane