Isivinini - izinkinga nezixazululo

Isivinini - izinkinga nezixazululo

1. Ibhola elingu-0.5-kg lihamba ngesivinini esingu-2 m/s. Bese ibhola lishaywa ngamandla F maqondana nesiqondiso sebhola , ngakho isivinini sebhola sishintshwa sibe ngu-6 m/s . Ibhola lithintana nomshayi isikhathi esingu -0.01 sesekhondi, kuyini ushintsho ekushukumeni kwebhola.

Kwaziwa:

Isisindo sebhola (m) = 0.5 kg

Ijubane lokuqala (v _o ) = 2 m/s

Ijubane lokugcina (v _t ) = -6 m/s

Isikhawu sesikhathi (t) = umzuzwana o-0.01

Okufunwayo: Ushintsho emgudwini

Isixazululo:

∆p = mv _t – mv _o = m (v _t – v _o )

∆p = (0.5 kg)(- 6 m/s – 2 m/s)

∆p = (0.5 kg)(-8)

∆p = 4 kg m/s

2. Into engamagremu ayi-100 ihamba ngesivinini esingu-5 m/s. I-Force F isebenza imizuzwana engu-0.2 ukumisa into. Thola ubukhulu bamandla F.

Kwaziwa:

Isisindo sento (m) = amagremu ayi-100 = 100/1000 = 0.1 kg

Ijubane lokuqala (v _o ) = 5 m/s

Ijubane lokugcina (v _t ) = 0

Isikhawu sesikhathi (Δt) = 0.2 imizuzwana

Okufunwayo: Ubukhulu bamandla F

Isixazululo:

I = ΔP

F (Δt) = m (v _t – vo _o )

F (0.2) = 0.1 (0 – 5)

F (0.2) = 0.1 (– 5)

F (0.2) = -0,5

F = -0,5 / 0.2

F = -2.5N

Ubukhulu bamandla F = 2.5 Newtons. Uphawu lokususa lubonisa isiqondiso samandla esiphambene nesiqondiso sento.

3. Ibhola elingamagremu ayi-100 liwa ngokukhululeka lisuka ekuphakameni okungu-20 cm ngaphandle kwejubane lokuqala bese ibhola lishaya phansi. Ngemva kokushayisana, ibhola liboniswa phezulu (ukusheshisa ngenxa yamandla adonsela phansi kungu-10 ms ^-2 ). Kuyini ushintsho kumfutho webhola.

Kwaziwa:

Isisindo sebhola (m) = amagremu angu-100 = 0.1 kg

Ukuphakama (h) = 20 cm = 0.2 amamitha

Ukusheshisa ngenxa yamandla adonsela phansi (g) = 10 m/s ²

Ijubane lebhola ngemva kokushaya phansi (v _t ) = 1 m/s

Okufunwayo: Ushintsho emgudwini

Isixazululo:

Ijubane lebhola ngaphambi kokushayisana (v _o )

Bala ijubane lebhola ngaphambi kokushayisana usebenzisa i-equation yokunyakaza kokuwa okukhululekile. Okuyaziwayo: ukuphakama kwebhola (h) = amamitha angu-0.2, ukusheshisa ngenxa yamandla adonsela phansi (g) = 10 m/s ² . Okufunwayo: ijubane lebhola uma lishaya phansi.

v ² = 2 gh

v ² = 2 (10)(0.2) = 4

v = √4 = -2 m/s

Uphawu lokususa lubonisa ukuthi indlela ibhola eliya ngayo ngaphambi kokushayisana iphambene nendlela ibhola eliya ngayo ngemva kokushayisana.

Ushintsho ku-momentum yebhola (Δp)

Δp = mv _t – mv _o = m (v _t – v _o )

Δp = (0.1)(1 – (-2)) = (0.1)(1 + 2) = (0.1)(3) = 0.3 Isekhondi likaNewton

4. Into eqale iphumule, iqhuma ibe izingxenye ezimbili ngesilinganiso esingu-3: 2. Ingxenye enkulu yobunzima iphonswa ngesivinini esingu-20 m/s. Iyini ijubane lengxenye encane.

Kwaziwa:

Isisindo sento 1 ngaphambi kokuqhuma = m

Ijubane lento 1 ngaphambi kokuqhuma = 0 (into iphumule)

Isisindo sengxenye enkulu ngemva kokuqhuma (m ₁ ) = 3m

Ubunzima bengxenye encane ngemva kokuqhuma (m2 ₎ = 2m

Ijubane lengxenye enkulu ngemva kokuqhuma (v ₁ ') = 20 m/s

Okufunwayo: Ijubane lengxenye encane ngemva kokuqhuma (v ₂ ')

Isixazululo:

Isilinganiso somthetho wokulondolozwa komfutho:

m ₁ v ₁ = m ₁ v ₁ ' + m ₂ v ₂ '

(m)(0) = (3m)(20) + (2m) v ₂ '

0 = 60m + (2m) v ₂ '

60m = -2m v ₂ '

60 = -2 v ₂ '

v ₂ ' = -60/2

v ₂ ' = -30 m/s

Uphawu lokususa lubonisa ukuthi indlela eya engxenyeni encane iphambene nendlela eya engxenyeni enkulu.

1. Kuyini umfutho?
   • Impendulo: I-Momentum iyinani le-vector elimelela umkhiqizo wesisindo sento kanye nejubane layo. Libonisa kokubili isiqondiso kanye nobukhulu bokunyakaza futhi livame ukufanekiswa yi- $p$, kuchazwa ngokuthi $p=mv$.
2. Umfutho uhluke kanjani kwijubane?
   • Impendulo: Nakuba kokubili umfutho kanye nesivinini kuyinani le-vector elihlobene nokunyakaza, ijubane lichaza kuphela ijubane kanye nesiqondiso sokunyakaza kwento, kanti umfutho ubheka kokubili isisindo sento kanye nejubane layo. Umfutho unikeza isilinganiso sokuthi kunzima kangakanani ukumisa into ehambayo.
3. Iyini isimiso sokugcina umfutho?
   • Impendulo: Isimiso sokulondolozwa komfutho sithi ohlelweni oluhlukanisiwe, umfutho ophelele ngaphambi kwesigameko (njengokushayisana) kumele ulingane nomfutho ophelele ngemva kwesigameko, uma nje kungekho mandla angaphandle asebenzayo ohlelweni.
4. Ukushukuma kuhlobene kanjani nomfutho?
   • Impendulo: I-Impulse ushintsho ku-momentum yento lapho amandla esetshenziswa esikhathini esithile. Inikezwa ngumkhiqizo wamandla nesikhathi asebenza ngaso, futhi ilingana noshintsho ku-momentum: $\text{Isisusa}=F\times \Delta t=\Delta p$.
5. Kungani ama-airbag ezimotweni esiza ekuvimbeleni ukulimala ngesikhathi sengozi?
   • Impendulo: Ama-airbag andisa isikhathi amandla asebenza ngaso kumuntu ogibele ngesikhathi sokushayisana. Lokhu kunciphisa amandla ajwayelekile atholwa ngumuntu ogibele. Ngobudlelwano bomfutho nomfutho, ukusabalalisa ushintsho lomfutho isikhathi eside kunciphisa amandla, kusize ekuvimbeleni ukulimala.
6. Uyini umehluko phakathi kokushayisana kwe-elastic kanye ne-inelastic ngokwe-momentum kanye ne-kinetic energy?
   • Impendulo: Kokubili ukushayisana kwe-elastic kanye ne-inelastic, i-momentum iyalondolozwa. Kodwa-ke, ekushayisane kwe-elastic, amandla e-kinetic aphelele nawo ayalondolozwa, kanti ekushayisane kwe-inelastic, akunjalo.
7. Umfutho ulondolozwa kanjani ekunyakazeni kokubuyela emuva kwesibhamu uma sidutshuliwe?
   • Impendulo: Uma isibhamu sidubula, inhlamvu iya phambili ngomfutho othile. Ukuze kulondolozwe umfutho ohlelweni oluhlukanisiwe (uma sicabanga ukuthi amandla angaphandle njengokumelana nomoya awabalulekile), isibhamu kumele sibuyele emuva ngomfutho olinganayo nophambene. Lokhu kunyakaza emuva kwaziwa ngokuthi ukubuyela emuva.
8. Kungani izinto ezinobukhulu obuhlukene ziwela ngesivinini esifanayo endaweni engenamuntu kodwa zibe nezikhathi ezihlukile?
   • Impendulo: Ku-vacuum, ukusheshisa okubangelwa amandla adonsela phansi kuyafana kuzo zonke izinto kungakhathaliseki ukuthi zinobunzima obunjani. Ngakho-ke, ubuningi obuhlukene buwa ngesivinini esifanayo. Kodwa-ke, umfutho uncike kokubili ejubaneni nasebunzini. Njengoba umfutho ungowokuthi $p=mv$, izinto ezimbili ezinesisindo esihlukene kodwa ijubane elifanayo lizoba nomzuzu ohlukile.
9. Umthetho wesithathu kaNewton uhlobana kanjani nokulondolozwa komfutho?
   • Impendulo: Umthetho wesithathu kaNewton uthi kuzo zonke izenzo, kukhona ukusabela okulinganayo nokuphambene. Lapho izinto ezimbili zihlangana, zisebenzisa amandla alinganayo naphikisanayo komunye nomunye ngesikhathi esifanayo, okusho ukuthi zithola izinguquko ezilinganayo neziphambene kumfutho. Lokhu kuphumela ekutheni umfutho ophelele ngaphambi kokuxhumana ulingane nomfutho ophelele ngemva kwalokho, ngaleyo ndlela kulondolozwe umfutho.
10. Kungani kulula ukumisa ibhayisikili elihambayo kunemoto ehambayo, noma ngabe zihamba ngesivinini esifanayo?

• Impendulo: Nakuba ibhayisikili nemoto kungaba nesivinini esifanayo, umfutho wazo uhlukile ngenxa yobukhulu bazo obuhlukene. Umfutho uncike kokubili esivinini nasesimeni. Imoto, njengoba inkulu kakhulu kunebhayisikili, inomfutho omkhulu ngesivinini esifanayo. Ngakho-ke, kudingeka umfutho omkhulu (noma ushintsho emsindweni) ukuze kumiswe imoto uma kuqhathaniswa nebhayisikili.