Paballo ea matla a mechini - mathata le litharollo
1. Boloko ba m-kg bo lokollwa ho tloha hodimo ho sefofane se sekametseng boreledi , jwalo ka ha ho bontshitswe setshwantshong se ka tlase. Papiso pakeng tsa matla a kgohedi le matla a kinetic a boloko ntlheng ya M ke…
tharollo
Matla a khoheli a ka bang teng ntlheng ea M:
PE M = mg (1/3h) = 1/3 mgh
Matla a kinetic ntlheng ea M:
KE M = EP = mg (2/3 h) = 2/3 mgh
EP M : EK M
1/3 mg: 2/3 mg
3/1: 3/2
1: 2
2. Moqhobi oa leqhoa ea thellang ho tloha bophahamong ba A, joalo ka ha ho bontšitsoe setšoantšong se ka tlase. Haeba lebelo la pele = 0 le ho potlaka ka lebaka la matla a khoheli e le 10 ms -2 , joale lebelo la moqhobi oa leqhoa ntlheng ea B ke lefe.
Tse tsejoang:
Lebelo la pele (v o ) = 0
Ho potlaka ka lebaka la matla a khoheli (g) = 10 m/s 2
Phetoho ea bophahamo = limithara tse 50 - limithara tse 10 = limithara tse 40
Ho batloa: Lebelo la motho ea thellang lehloa ntlheng ea B
Tharollo:
Molao-motheo oa paballo ea matla a mechine o bolela hore matla a pele a mechini = matla a ho qetela a mechini.
Matla a pele a mechini = matla a ka bang teng ntlheng ea B (bophahamo = limithara tse 40)
Matla a ho qetela a mechini = matla a kinetic ntlheng ea B
Matla a ho qetela a mechini = Matla a pele a mechini
½ mv t 2 = mgh
½ v t 2 = gh
½ v t 2 = (10)(50-10)
½ v t 2 = (10)(40)
½ v t 2 = 400
v t 2 = (2)(400) = 800
v t = √800 = √(2)(400) = 20√2 m/s
3. Ntho e qala ho thella ho tloha ntlheng ea A ntle le lebelo la pele. Haeba ho se na matla a khohlano, lebelo la ntho ntlheng e tlase ke lefe.
Tse tsejoang:
Boima ba ntho = m
Lebelo la pele (v o ) = 0
Bophahamo (h) = limithara tse 20
Ho potlaka ka lebaka la matla a khoheli (g) = 10 m/s 2
Ho batloa: Lebelo la ho qetela (v t )
Tharollo:
Matla a pele a mechini (ME 1 ) = Matla a khoheli a ka bang teng ntlheng ea A (PE A ) = mgh = (m)(10)(20) = 200 m
Matla a ho qetela a mechini (ME 2 ) = matla a kinetic (KE) = ½ mv t 2
Lebelo la ntho ntlheng e tlase ka ho fetisisa (v t )?
Sebelisa molao-motheo oa paballo ea matla a mechine o bolela hore matla a pele a mechini = matla a ho qetela a mechini.
EM1 = EM2
200 m = ½ mv t 2
200 = ½ v t 2
400 = v t 2
v t = 20 m/s
4. Bolo e sa lefelloeng ea 2-kg e oa ho tloha ntlheng ea A, joalo ka ha ho bontšitsoe setšoantšong se ka tlase (g = 10 ms -2 ). Kamora ho fihla ntlheng ea B, matla a kinetic = matla a ka bang teng a makhetlo a 2. Bolelele ba ntlha ea B ka holim'a lefatše ke bofe.
Tse tsejoang:
Boima ba bolo (m) = 2 kg
Ho potlaka ka lebaka la matla a khoheli (g) = 10 ms -2
Bophahamo ba ntlha A (h A ) = limithara tse 90
Ho batloa: Bophahamo ba ntlha B (h B )
Tharollo:
Ha o fihla ntlheng ea B, matla a kinetic a bolo ntlheng ea B = matla a khoheli a matla a khoheli a fetang a mabeli ntlheng ea B.
EK = 2 EP
½ mv 2 = 2 mph B
½ v 2 = 2 gh B
v 2 = 2(2)(10) h B
v 2 = 40 h B
Lebelo (v) la bolo ha e fihla ntlheng ea B kamora ho oa mahala ho tloha ntlheng ea A:
v 2 = 2 gh = 2(10)(90–h B ) = 20(90–h B )
Kenya v 2 ho equation e kaholimo le v 2 ho equation ena.
v 2 = 40 h B
20(90–lihora B ) = 40 lihora B
1800–20 lihora B = 40 lihora B
1800 = 40 lihora B + 20 lihora B
1800 = lihora tse 60 B
h B = 1800 / 60
h B = limithara tse 30
5. Bolo ea 1-kg e lokolloa 'me e thellela tlase ho tloha ntlheng ea A ho ea ntlheng ea C, joalo ka ha ho bontšitsoe setšoantšong se ka tlase. Haeba ho potlaka ka lebaka la matla a khoheli = 10 ms -2 , matla a kinetic a bolo ke afe ha e fihla ntlheng ea C?
Tse tsejoang:
Boima ba bolo (m) = 1 kg
Ho potlaka ka lebaka la matla a khoheli (g) = 10 m/s 2
Phetoho ea bophahamo (h) = 0.75 m
Matla a pele a ka bang teng (PE o ) = mgh = (1)(10)(0.75) = 7.5 Joules
Matla a kinetic a pele (KE o ) = ½ mv o 2 = ½ m (0) 2 = 0
Matla a ho qetela a khoheli (PE t ) = mgh = mg (0) = 0
Ho batloa: Matla a kinetic a bolo ntlheng ea C
Tharollo:
Matla a pele a mechini (ME o ) = Matla a ho qetela a mechini (ME t )
Matla a pele a khoheli (PE o ) + matla a pele a kinetic (KE o ) = Matla a ho qetela a khoheli (PE t ) + matla a ho qetela a kinetic (KE t )
Li-joule tse 7.5 + 0 = 0 + KE t
Li-joule tse 7.5 = KE t
Matla a kinetic a bolo ntlheng ea C = 7.5 Joules.
6. Bolo ea 2-kg e lokolloa ho tloha ntlheng ea A, joalo ka ha ho bontšitsoe setšoantšong se ka tlase. Sekhutlo se boreleli. Haeba lebelo le bakoang ke matla a khoheli e le 10 ms -2 , matla a kinetic a bolo ntlheng ea B ke afe.
Tse tsejoang:
Boima ba bolo (m) = 2 kg
Ho potlaka ka lebaka la matla a khoheli (g) = 10 m/s 2
Phetoho ea bophahamo (h) = 120 cm = 1.2 metres
Matla a pele a khoheli (PE o ) = mgh = (2)(10)(1.2) = 24 Joules
Matla a kinetic a pele (KE o ) = ½ mv o 2 = ½ m (0) 2 = 0
Matla a ho qetela a khoheli (PE t ) = mgh = mg (0) = 0
Ho batloa: Matla a kinetic a bolo ntlheng ea B
Tharollo:
Matla a mechini ntlheng ea A (matla a pele a mechini) = matla a mechini ntlheng ea B (matla a ho qetela a mechini)
Matla a pele a mechini (ME o ) = matla a ho qetela a mechini (ME t )
Matla a pele a khoheli (PE o ) + matla a pele a kinetic (KE o ) = matla a ho qetela a khoheli (PE t ) + matla a ho qetela a kinetic (KE t )
Li-joule tse 24 + 0 = 0 + KE t
Li-joule tse 24 = KE t
Matla a kinetic (KE) a bolo ntlheng ea C = 24 Joules.
7. Ntho e na le matla a tsitsitseng a mechini, matla a maholo a kinetic, le matla a manyane a khoheli. Ntho ke…
A. Phomolong
B. nyolohela holimo
C. theohela tlase
D. E potlakisitswe ho ya hodimo
Tharollo:
Matla a kinetic a ntse a hola ho bolelang hore lebelo la ntho le ntse le hola mme matla a khoheli a fokolang ho bolelang hore bophahamo ba ntho ho tloha hodima mobu bo bonyenyane. Sena se etsahala ha ntho e tloha bophahamong bo itseng ho ya fatshe.
Kamano pakeng tsa lebelo le matla a kinetic e bontšoa ke foromo ea matla a kinetic:
KE = ½ mv 2
Tlhaloso ea foromo: KE = matla a kinetic, m = boima, v = lebelo
Kamano pakeng tsa bophahamo le matla a khoheli e emetsoe ke foromo ea matla a khoheli:
PE = mgh
Tlhaloso ea foromo: PE = matla a khoheli a ka bang teng, m = boima, g = ho potlaka ha matla a khoheli, h = bolelele
Karabo e nepahetseng ke C.
- Matla a mechini ke eng?
- Araba: Matla a mechini ke kakaretso ea matla a kinetic le matla a ka bang teng a ntho. Matla a kinetic a amana le motsamao oa ntho, ha matla a ka bang teng a amana le boemo ba eona kapa sebopeho sa eona.
- Molao-motheo oa paballo ea matla a mechini o bolela eng?
- Araba: Molao-motheo o bolela hore tsamaisong e arohaneng e nang le matla a bolokang lintho feela a sebetsang, matla ohle a mechini a lula a sa fetohe. Seo se bolela hore kakaretso ea matla a kinetic le a ka bang teng ha e fetohe ha nako e ntse e ea.
- Matla a bolokang lintho ka mokhoa o itekanetseng le a sa bolokeng lintho ka mokhoa o feteletseng a ama paballo ea matla a mechini joang?
- Araba: Matla a bolokang, joalo ka matla a khoheli, ha a fetole matla ohle a mechini a sistimi. A ka fetola matla a ka bang teng ho ba matla a kinetic kapa ka tsela e fapaneng, empa kakaretso e lula e tsitsitse. Matla a seng a bolokang, joalo ka khohlano, a ka qhalanya matla a mechini, hangata a a fetola matla a mocheso.
- Ke hobane'ng ha matla a mechini a sa bolokoe maemong a sebele a amanang le khohlano?
- Araba: Khohlano ke matla a sa bolokeheng. Ha lintho li ntse li atamelana, khohlano e fetola matla a mang a mechini a sistimi hore e be matla a mocheso, e leng se lebisang phokotsong ea matla ohle a mechini a sistimi.
- Ho boloka matla a mechini ho bontšoa joang ka har'a pendulum e ntseng e thekesela?
- Araba: Ha ho se na khanyetso ea moea (matla a sa bolokeheng), ha pendulum e ntse e phahama, matla a eona a kinetic a fetoloa matla a khoheli. Sebakeng se phahameng ka ho fetisisa sa ho sisinyeha ha eona, e na le matla a maholo a ka bang teng le matla a bonyane a kinetic. Ha e ntse e khutlela tlase, matla ana a ka bang teng a fetoloa hape hore e be matla a kinetic. Matla ohle a mechini a lula a sa fetohe, leha mefuta ea matla e ntse e fetoha.
- Ke hobane'ng ha bolo e tlolang e qetella e phomotse leha ho se na matla a kantle?
- Araba: Ha bolo e tlola, ha se matla ohle a yona a kinetic a kgutlisetswang ho ba matla a ka bang teng. Matla a mang a lahleha, hangata e le modumo kapa e le phetoho ya bolo, haholoholo ka lebaka la kgohlano ya ka hare ka hara thepa ya bolo. Tsena ke mefuta ya matla a sa bolokeheng a bapalang, a fokotsang matla a mechini a bolo ka ho tlola ho hong le ho hong ho fihlela e phomola.
- Ka har'a roller coaster, matla a mechini a phahameng ka ho fetisisa le a tlase ka ho fetisisa a hokae?
- Araba: Matla ohle a mechini a roller coaster a dula a tsitsitse haeba re hlokomoloha ho hanyetsa moya le kgohlano. Leha ho le jwalo, ntlheng e hodimo, matla a ka bang teng a hodimo ha matla a kinetic a le tlase. Ha a theoha, matla a ka bang teng a fetoha matla a kinetic, kahoo ntlheng e tlase, matla a kinetic a hodimo mme matla a ka bang teng a hodimo.
- Ho boloka matla a mechini ho thusa joang ho utloisisa potoloho ea lipolanete?
- Araba: Lipolanete tse potolohang naleli e kang Letsatsi li na le matla a kinetic (ka lebaka la motsamao oa tsona) le matla a khoheli (ka lebaka la boemo ba tsona ha li bapisoa le Letsatsi). Ha polanete e ntse e atamela Letsatsi, e potlakisa, e eketsa matla a eona a kinetic ha matla a eona a khoheli a fokotseha, 'me ka tsela e fapaneng. Matla ohle a mechini a polanete a lula a tsitsitse ha nako e ntse e ea, ho nahanoa hore matla a mang (joalo ka a tsoang lipolaneteng tse ling) ha a bohlokoa.
- Ke hobane'ng ha sathelaete e potolohang ka mokhoa o tsitsitseng e sa oele Lefatšeng?
- Araba: Leha sathelaete e hlile e huleloa Lefatšeng ka lebaka la matla a khoheli, matla a eona a kinetic a pele a e boloka e tsamaea potolohong ea eona. Tekanyo ea matla ana a kinetic le matla a khoheli a boloka sathelaete e le potolohong e tsitsitseng ka matla a sa khaotseng a mechini.
- Haeba motho ea thellang ka lehloa a qala a phomotse holimo leralleng le se nang khohlano ebe o thella, lebelo la hae le tlase le tla ba joang ha le bapisoa le haeba a ka qala ho theoha leralleng hanyane?
- Araba: Leralleng le se nang khohlano, matla ohle a mechine a motho ea thellang lehloeng aa bolokoa. Haeba a qala ho tloha holimo, o tla ba le matla a mangata a ho qala ho feta haeba a qala ho theoha hanyane. Matla ana a tla fetoha ka botlalo matla a kinetic ha a theoha. Kahoo, o tla ba lebelo tlase haeba a qala ho theoha hanyane ho feta haeba a qala ho theoha hanyane.
