Amandla amakhulu - izinkinga nezixazululo
1. Ibhulokhi yokhuni enobude = 2.5 m, ububanzi = 0.5 m kanye nokuphakama = 0.4 m. Ubuningi bamanzi buyi-1000 kg/m 3. Uma ibhulokhi ifakwa emanzini, ayini amandla okuphaphazela ... Ukusheshisa ngenxa yamandla adonsela phansi kungu-10 N/kg.
Kwaziwa:
Umthamo webhulokhi (V) = ubude x ububanzi x ukuphakama = 2.5 x 0.5 x 0.4 = 0.5 m 3
Ubuningi bamanzi (ρ) = 1000 kg/ m3
Ukusheshisa ngenxa yamandla adonsela phansi (g) = 10 N/kg
Okufunwayo: Ubukhulu bamandla anamandla
Isixazululo:
Ifomula yamandla athambile:
F = ρ g V
F = amandla okuphaphazela , ρ = ukuminyana kwamanzi , g = ukusheshisa ngenxa yamandla adonsela phansi , V = ivolumu
F = (1000)(10)(0.5) = (1000)(5) = 5000 amaNewton
2. Isisindo sento esemoyeni singama-N ayi-100. Into ifakwa oketshezini. Ukwanda kwevolumu yoketshezi kungu-1.5 m 3. Uma isisindo esithile soketshezi singama-N ayi-10/m 3 , siyini isisindo sento eseketshezini.
Kwaziwa:
Isisindo sento emoyeni (w) = amaNewton ayi-100
Ukwanda kwevolumu yoketshezi = ivolumu yento eketshezini (V) = 1.5 m 3
Isisindo esithile soketshezi = 10 N/m 3
Okufunwayo: Isisindo sento ngoketshezi
Isixazululo:
Isisindo sento kuketshezi = isisindo sento emoyeni – amandla athambile
Isisindo sento ngoketshezi = 100 Newton – amandla okuphapha
Ifomula yamandla athambile:
F A = ρ g V
F A = amandla avuselelayo = amandla asetshenziswa uketshezi entweni esemanzini
ρ = ukuminyana koketshezi
g = ukusheshisa ngenxa yamandla adonsela phansi
V = ivolumu yento kuketshezi
Isisindo esithile:
Isisindo esithile soketshezi = 10 N/m 3
w / V = 10 N/m 3
mg / V = 10 N/m 3
m (10) / V = 10 N/m 3
m / V = 1 kg/m 3
ρ = 1 kg/m 3
Ubuningi boketshezi buyi-1 kg/ m3
Ubukhulu bamandla athambile :
F A = ρ g V = (1 kg/m 3 )(10 m/s 2 )(1.5 m 3 ) = 15 kg m/s 2 = 15 AmaNewton
Isisindo sento ngoketshezi:
Isisindo sento ngoketshezi = 100 Newtons – 15 Newtons
Isisindo sento ngoketshezi = 85 Newtons
3. Umkhumbi ohamba olwandle ungena emfuleni obanzi nojulile. Ubuningi bamanzi olwandle bungu-1100 kg/m3 , ubuningi bamanzi omfula bungu - 1000 kg/ m3 . Thola ukuqhathanisa umthamo wento esemanzini olwandle nasemanzini omfula.
A. 11: 10
B. 10: 11
C. 121: 100
D. 1: 1
Kwaziwa:
Ubuningi bamanzi olwandle (ρ 1 ) = 1100 kg/ m3
Ubuningi bamanzi omfula (ρ 2 ) = 1000 kg/ m3
Okufunwayo: Ukuqhathaniswa komthamo wento esemanzini olwandle nasemanzini omfula . Ukuqhathaniswa komthamo wento esemanzini olwandle nasemanzini omfula.
Isixazululo:
Uma into intanta khona-ke amandla okuphapha (F B ) = isisindo (w):

Isimiso sika- Archimedes sithi amandla ashukumisayo asebenza entweni ewuketshezi (amanzi) alingana nesisindo soketshezi (amanzi) olususayo. Umthamo wento ewuketshezi (amanzi) ulingana nomthamo woketshezi (amanzi) olunyakaziswayo.
Ukuqhathaniswa komthamo wento emanzini olwandle kanye nase- amanzi omfula:

Impendulo efanele ngu-B.
4. Igolide, elinobunzima obungamagremu angu-193 lise-kerosene enamandla aphezulu angama-dynes angu-8000. Uma ukusheshisa ngenxa yamandla adonsela phansi kungu-10 m/s 2 kanti ubuningi be -kerosene bungu-0.8 gr/cm 3 , khona-ke nquma ubuningi begolide.
A. 1.93 gr/ cm3
B. 8.65 gr/ cm3
C. 19.3 gr/ cm3
D. 193 gr/ cm3
Kwaziwa:
Isisindo segolide (m igolide ) = 193 amagremu = 0.193 kg
Ukusheshisa ngenxa yamandla adonsela phansi (g) = 10 m/s 2
Amandla okuqina (F A ) = 8000 dyne = 8 x 10 3 dyne = (8 x 10 3 )(10 -5 N) = 8 x 10 -2 N = 0.08 Newton
Ubuningi be-parafini (ρ) = 0.8 gr/cm 3 = 800 kg/m 3
Okufunwayo: Ubuningi begolide
Isixazululo:
Isisindo segolide emoyeni:
w = mg = ρ b V g —– Isibalo 1
U-V umqulu wegolide ku-parafini.
Amandla amakhulu (F B ) alingana nesisindo segolide emoyeni (w) ngaphandle kwesisindo segolide ku-kerosene (w'):
w – w' = F A
w – w' = ρ f V g —– Isibalo 2
U-V umqulu wegolide ku-parafini.
Zombili izilinganiso ezingenhla zingabhalwa futhi ngezansi:


Impendulo efanele ithi C.
- Iyini isimiso esiyisisekelo samandla anamandla?
- Impendulo: Isimiso esiyisisekelo samandla okuphapha yiSimiso sika-Archimedes. Sithi into ecwiliswe oketshezini ithola amandla aphezulu abizwa ngokuthi amandla okuphapha alingana ngobukhulu nesisindo soketshezi olususwe yinto.
- Kungani into izwakala ilula uma icwiliswe emanzini?
- Impendulo: Uma into icwiliswe emanzini, isusa umthamo othile wamanzi. Isisindo sala manzi asusiwe sisebenzisa amandla akhuphukayo entweni, alwa nesisindo sento, okwenza izwakale ilula.
- Uma into intanta emanzini, isisindo sayo siqhathaniswa kanjani namandla asebenza kuyo?
- Impendulo: Uma into intanta, amandla okuphapha asebenza kuyo alingana nesisindo sento. Yingakho into ihlala isesimweni esilinganayo ngaphandle kokucwila noma ukukhuphuka.
- Ingabe amandla okuphapha ayasebenza ezintweni ezisemoyeni?
- Impendulo: Yebo, amandla okuphapha asebenza ezintweni ezikunoma yiluphi uketshezi, okuhlanganisa nomoya. Kodwa-ke, ngenxa yokuthi umoya awuqinile kakhulu kuneziketshezi ezifana namanzi, amandla okuphapha emoyeni mancane kakhulu futhi ngokuvamile awabalulekile ezintweni zansuku zonke.
- Kungani ezinye izinto zicwila emanzini kanti ezinye zintanta emanzini?
- Impendulo: Ukuthi into iyacwila noma iyantanta kuncike ebuhlotsheni obuphakathi kwesisindo sayo namandla okuntanta. Uma amandla okuntanta (ngenxa yoketshezi olususiwe) makhulu kunesisindo sento, iyantanta. Uma isisindo sikhulu, iyacwila.
- Uma ubungathatha ibhola lensimbi elingenalutho kanye nebhola lensimbi eliqinile elinobukhulu obufanayo kanye nezinto ezifanayo, bese ulicwilisa emanzini, yiliphi elingaba namandla amakhulu okuphapha?
- Impendulo: Amandla okuphapha ancike kumthamo woketshezi oluphumile hhayi kubunzima bento. Njengoba womabili amabhola esusa umthamo ofanayo wamanzi, azozwa amandla afanayo okuphapha.
- Kungani imikhumbi eyenziwe ngensimbi, eqine kakhulu kunamanzi, intanta?
- Impendulo: Imikhumbi yaklanywa ngezikhala ezinkulu ezingenalutho ngaphakathi, okusho ukuthi isilinganiso sayo esijwayelekile singaphansi kwesamanzi. Amanzi asuswa umkhumbi anamandla okuphapha angasekela isisindo somkhumbi, awenze untante.
- Uma ucindezela ibhola elintantayo emanzini bese ulidedela, kuzokwenzekani?
- Impendulo: Uma ucindezela ibhola elintantayo lijule emanzini, ukhulisa umthamo wamanzi eliwususayo, okwandisa amandla okugobhoza. Uma ulikhulula, amandla okugobhoza akhuphukile azolisunduzela phezulu lize libuyele esimweni salo sokulingana.
- Kwenzekani emandleni athambile entweni ecwiliswe emanzini uma uyisusa emanzini ahlanzekile uyiyise emanzini anosawoti?
- Impendulo: Amanzi anosawoti aminyene kunamanzi ahlanzekile. Ngakho-ke, ngomthamo ofanayo osusiwe, amandla okugeleza emanzini anosawoti azoba makhulu kunamanzi ahlanzekile. Ngakho-ke, into ingase intante kakhulu emanzini anosawoti kunamanzi ahlanzekile.
- Kungenzeka yini ukuthi into iqine kwenye indawo (isb., iqonde phezulu) kodwa ingazinzile kwenye (isb., iqonde phezulu) ngenkathi intanta emanzini?
- Impendulo: Yebo, ukuzinza kwento entantayo kuncike ekusatshalalisweni kwesisindo sayo uma kuqhathaniswa namandla athambile. Uma isikhungo samandla adonsela phansi singaphezu ngqo kwesikhungo sokuthambile, into izozinza. Kodwa-ke, uma ushintsha indlela eqondiswa ngayo, ubudlelwano phakathi kwezikhungo bungashintsha, okuholela ekungazinzini kuleyo ndlela ethile.