Isimiso samandla okusebenza nokwemishini
Ithiyori yamandla okusebenza-kinetic ithi umsebenzi we-net noma umsebenzi owenziwe amandla e-net ulingana noshintsho lwamandla e-kinetic.
I-W inethi = TO t – TO o = 1⁄2 m(v t 2 – vo 2 )
I-W net = Kunezinhlobo ezimbili zamandla, okungukuthi amandla okulondoloza, kanye namandla angewona awokulondoloza. Ngakho-ke, umsebenzi we-net ungabhekwa njengowakhiwe umsebenzi owenziwe amandla okulondoloza kanye nomsebenzi owenziwe amandla angewona awokulondoloza.
W c + W nc = ΔKE
Umsebenzi owenziwa amandla alondolozayo ulingana noshintsho olubi emandleni angaba khona:
W c = -ΔPE
– ΔPE + W nc = ΔKE
W nc = ΔPE + ΔKE
I-Wnc = ΔME
Isibalo esingenhla sithi umsebenzi owenziwa amandla angewona awokugcina izinto entweni ulingana noshintsho emandleni okusebenza entweni. Amandla okusebenza = amandla angase abe khona + amandla e-kinetic. Amandla angase abe khona angathatha isimo samandla angase abe khona adonsela phansi noma amandla angase abe khona anwebekayo.
Isibonelo sombuzo: Ithiyori yamandla okusebenza-okusebenza
Ibhokisi elingama-2 kg liqala lihamba ngesivinini esingu-10 m/s. Ngemva nje kwalokho, ibhokisi liyama. I-coefficient of kinetic friction phakathi kwebhokisi nephansi ingu-0.2. Ukusheshisa kwamandla adonsela phansi kungu-10 m/s 2 . Kungakanani ukufuduka kwebhokisi?
Ingxoxo:
Kuhlonziwe: m = 2 kg, v o = 10 m/s, vt = 0, k = 0.2, w = mg = (1 kg)(10 m/s 2 ) = 10 kg m/s 2 = 10 AmaNewton,
Kubuziwe: inani lokufuduka kwebhokisi (ama)
Ithiyori yamandla okusebenza-okusebenza:
W nc = ΔME
W nc = ΔPE + ΔKE
Ukuphakama (h) kuhlala kungaguquki noma akukho shintsho ekuphakameni, ngakho-ke akukho shintsho emandleni adonsela phansi.
I-Wnc = ΔKE
Umsebenzi owenziwa amandla okungqubuzana kwe-kinetic yilo:
W nc = – f k s = μ k N -s = μ k w -s = μ k mg -s
I-W nc = – (0.2)(2)(10)(s) = – (4)(s)
Amandla okungqubuzana kwe-kinetic enza umsebenzi ongemuhle (amandla okungqubuzana kwe-kinetic akwelinye icala eliphambene nokufuduka kwento)
Ushintsho kumandla e-kinetic:
ΔKE = 1⁄2 m (v t 2 – vo 2 ) = 1⁄2 (2)(0 2 – 10 2 ) = (0 – 100) = – 100
Ukufuduka kwento:
W nc = ΔKE
– (4)(s) = – 100
s = – 100 / – 4 = amamitha angu-25
Imibuzo nezimpendulo ezingu-20 eziphathelene nomgomo wamandla okusebenza-okusebenza:
1. Umbuzo: Uyini umgomo wamandla okusebenza-omshini? Impendulo: Umgomo wamandla okusebenza-omshini uthi umsebenzi owenziwa entweni ulingana noshintsho lwamandla ayo omshini.
2. Umbuzo: Umsebenzi uchazwa kanjani ku-physics? Impendulo: Umsebenzi uchazwa njengomkhiqizo wamandla asetshenziswa entweni kanye nebanga elihamba ngalo lapho amandla efika khona.
3. Umbuzo: Yini eyakha amandla omshini? Impendulo: Amandla omshini aqukethe amandla omshini kanye namandla angase abe khona entweni.
4. Umbuzo: Uma kungekho amandla angewona awokugcina izinto, yini engashiwo ngamandla aphelele okusebenza kwesistimu evaliwe? Impendulo: Amandla aphelele okusebenza kwemishini ahlala engaguquki.
5. Umbuzo: Nikeza isibonelo samandla alondolozayo. Impendulo: Amandla adonsela phansi ayisibonelo samandla alondolozayo.
6. Umbuzo: Amandla angase ahluke kanjani kumandla e-kinetic? Impendulo: Amandla angase angase avele ngenxa yesikhundla, njengokuphakama ngaphezu komhlaba, kuyilapho amandla e-kinetic evele ngenxa yokunyakaza.
7. Umbuzo: Umsebenzi owenziwa amandla alondolozayo uhlobana kanjani namandla angase abe khona? Impendulo: Umsebenzi owenziwa amandla alondolozayo ulingana noshintsho olubi emandleni angase abe khona.
9. Umbuzo: Isimiso samandla okusebenza-nomshini sikuchaza kanjani ukuguqulwa kwamandla angase abe amandla e-kinetic entweni ewa ngokukhululeka? Impendulo: Njengoba into iwa, amandla ayo angase anciphe futhi amandla ayo e-kinetic ayanda ngenani elilinganayo, okugcina amandla aphelele omshini engaguquki.
10. Umbuzo: Kwenzekani emandleni omshini wesistimu lapho amandla angewona awokugcina izinto, njengokungqubuzana, esebenza kuwo? Impendulo: Amandla omshini ayancipha ngoba amandla angewona awokugcina izinto achitha amandla, ngokuvamile njengokushisa.
11. Umbuzo: Ingabe amandla omshini ohlelweni anganda? Impendulo: Yebo, uma kwenziwa umsebenzi wangaphandle ohlelweni.
12. Umbuzo: Umqondo womsebenzi uhlobene kanjani namandla? Impendulo: Umsebenzi uyindlela amandla adluliselwa noma aguqulwa ngayo ohlelweni.
13. Umbuzo: Uma into ihamba ngesivinini esingaguquki, yini engashiwo ngomsebenzi wenethi owenziwe kuyo? Impendulo: Umsebenzi wenethi owenziwe kuyo awukho ngoba akukho ukusheshisa okwenzekayo.
15. Umbuzo: Kungani isiphethu esicindezelwe sinamandla angase asebenze? Impendulo: Uma isiphethu sicindezelwe, kwenziwa umsebenzi kuso, ogcinwa njengamandla angase asebenze. La mandla angakhishwa uma isiphethu sidedelwa.
16. Umbuzo: Iyini i-work-energy theorem? Impendulo: I-work-energy theorem ithi umsebenzi owenziwa entweni ulingana noshintsho lwamandla ayo e-kinetic.
17. Umbuzo: Amandla ahlobene kanjani nomsebenzi? Impendulo: Amandla yisilinganiso lapho umsebenzi wenziwa khona noma amandla adluliselwa khona. Kubalwa njengo- , lapho ewumsebenzi kanti ewusikhathi.
18. Umbuzo: Ingabe umsebenzi ungaba nenani elibi? Impendulo: Yebo, umsebenzi ungaba nenani elibi uma amandla kanye nesiqondiso sokunyakaza kuphambene.
19. Umbuzo: Uma i-engeli ephakathi kwamandla kanye nesiqondiso sokunyakaza ingama-degrees angu-90, yimuphi umsebenzi owenziwayo? Impendulo: Umsebenzi owenziwe u-zero ngoba amandla awanaso isakhi esiqondisweni sokunyakaza.
20. Umbuzo: Umshini olula, njenge-lever, wenza kanjani umsebenzi ube lula? Impendulo: I-lever ayishintshi umsebenzi wonke owenziwe kodwa ishintsha indlela amandla asetshenziswa ngayo, okwenza umsebenzi uphathwe kalula noma usebenze kahle.
Umqondo womsebenzi kanye nesimiso samandla okusebenza ngomshini kuyisisekelo ku-physics futhi kunikeza ukuqonda okuyisisekelo kokuthi amandla adluliselwa futhi aguqulwa kanjani ezinhlelweni ezahlukene.
