Momentum - matsaloli da mafita

Momentum - matsaloli da mafita

1. Kwallo mai nauyin kilogiram 0.5 tana motsawa a mita 2/s. Sannan ana buga ƙwallon da ƙarfi F a gaban alkiblar ƙwallon , don haka ana canza saurin ƙwallon zuwa mita 6/s . Kwallo tana hulɗa da mai bugawa na tsawon daƙiƙa 0.01, menene canjin saurin ƙwallon.

An sani:

Nauyin ƙwallon (m) = 0.5 kg

Saurin farko (v _o ) = 2 m/s

Saurin ƙarshe (v _t ) = -6 m/s

Tazarar lokaci (t) = daƙiƙa 0.01

Ana so: Sauyin yanayin aiki

Magani:

∆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. Abu mai nauyin gram 100 yana motsawa a gudun mita 5/s. Ƙarfin F yana aiki na daƙiƙa 0.2 don tsayar da abin. A tantance girman ƙarfin F.

An sani:

Nauyin abu (m) = gram 100 = 100/1000 = 0.1 kg

Saurin farko (v _o ) = 5 m/s

Saurin ƙarshe (v _t ) = 0

Tazarar lokaci (Δt) = daƙiƙa 0.2

Ana nema: Girman ƙarfi F

Magani:

I = ΔP

F (Δt) = m (v _t – v _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

Girman ƙarfi F = 2.5 Newtons. Alamar da ba ta da shi tana nuna alkiblar ƙarfi da ke gaban alkiblar abin.

3. Kwallo mai nauyin gram 100 ta faɗi daga tsayin santimita 20 ba tare da saurin farko ba sannan ƙwallon ta faɗi ƙasa. Bayan karo, ƙwallon tana nuna sama (ƙarfin da ke faruwa saboda nauyi shine 10 ms ^-2 ). Menene canjin motsin ƙwallon.

An sani:

Nauyin ƙwallon (m) = gram 100 = 0.1 kg

Tsawo (h) = 20 cm = mita 0.2

Saurin gudu saboda nauyi (g) = 10 m/s ²

Gudun ƙwallo bayan buga ƙasa (v _t ) = 1 m/s

Ana so: Sauyin yanayin aiki

Magani:

Gudun ƙwallon kafin karo (v _o )

Lissafin saurin ƙwallon kafin karo ta amfani da lissafin motsin faɗuwa kyauta. An sani: tsayin ƙwallon (h) = mita 0.2, hanzari saboda nauyi (g) = 10 m/s ^2. Ana so: saurin ƙwallon lokacin da ya faɗi ƙasa.

v ² = 2 gh

v ² = 2 (10)(0.2) = 4

v = √4 = -2 m/s

Alamar ragewa tana nuna cewa alkiblar ƙwallon kafin karo tana akasin alkiblar ƙwallon bayan karo.

Canjin motsin ƙwallon (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 Daƙiƙa na Newton

4. Da farko wani abu yana hutawa, ya fashe zuwa sassa 2 tare da rabon 3: 2. Babban ɓangaren nauyin ana jefa shi a gudun 20 m/s. Menene saurin ƙaramin ɓangaren.

An sani:

Yawan abu 1 kafin fashewa = m

Gudun abu 1 kafin fashewa = 0 (abu a hutawa)

Nauyin babban ɓangaren bayan fashewar (m ₁ ) = 3m

Nauyin ƙaramin sashi bayan fashewa (m2 ₎ = 2m

Gudun babban ɓangaren bayan fashewar (v ₁ ') = 20 m/s

Ana so: Saurin ƙaramin sashi bayan fashewa (v ₂ ')

Magani:

Daidaiton dokar kiyaye ƙarfin motsi:

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

Alamar da aka rage tana nuna cewa alkiblar ƙaramin ɓangaren ta saba wa alkiblar babban ɓangaren.

1. Menene saurin yanayi?
   • amsa: Momentum adadi ne na vector wanda ke wakiltar samfurin nauyin abu da saurinsa. Yana nuna duka alkibla da girman motsi kuma galibi ana nuna shi ta hanyar $p$, an ayyana shi azaman $p=mv$.
2. Ta yaya ƙarfin motsi ya bambanta da saurin gudu?
   • amsa: Duk da cewa duka ƙarfin motsi da saurin gudu suna da alaƙa da motsi, saurin gudu yana bayyana gudu da alkiblar motsin abu ne kawai, yayin da ƙarfin motsi yana la'akari da nauyin abu da saurinsa. Momentum yana ba da ma'auni na yadda yake da wahala a dakatar da abu mai motsi.
3. Menene ƙa'idar kiyaye ƙarfin kuzari?
   • amsa: Ka'idar kiyaye ƙarfin motsi ta bayyana cewa a cikin tsarin da aka keɓe, jimlar ƙarfin motsi kafin wani abu (kamar karo) dole ne ya zama daidai da jimlar ƙarfin motsi bayan abin ya faru, muddin babu wani ƙarfin waje da ya yi aiki akan tsarin.
4. Ta yaya motsin rai yake da alaƙa da motsin rai?
   • amsa: Impulse shine canjin motsin abu idan aka yi amfani da karfi a wani takamaiman lokaci. Ana bayar da shi ta hanyar samfurin ƙarfin da lokacin da yake aiki, kuma yana daidai da canjin motsin: $\text{turu}=F\times \Delta t=\Delta p$.
5. Me yasa jakunkunan iska a cikin motoci ke taimakawa wajen hana raunuka yayin karo?
   • amsa: Jakunkunan iska suna ƙara lokacin da ƙarfin ke aiki akan mai shiga yayin karo. Wannan yana rage matsakaicin ƙarfin da mai shiga ke fuskanta. Ta hanyar alaƙar motsin rai da motsin rai, yaɗa canjin motsi a cikin dogon lokaci yana rage ƙarfin, yana taimakawa wajen hana raunuka.
6. Mene ne bambanci tsakanin karo na roba da na inelastic dangane da motsi da kuzarin motsi?
   • amsa: A cikin karo na roba da na inelastic, ana kiyaye ƙarfin motsi. Duk da haka, a cikin karo na roba, ana kiyaye cikakken kuzarin motsi, yayin da a cikin karo na inelastic, ba haka ba ne.
7. Ta yaya ake kiyaye ƙarfin motsi a cikin motsin juyawar bindiga lokacin da aka harba ta?
   • amsa: Idan aka harba bindiga, harsashin yana tafiya gaba da wani motsi. Domin kiyaye motsi a cikin tsarin da aka keɓe (idan aka yi la'akari da cewa ƙarfin waje kamar juriyar iska ba su da yawa), bindigar dole ne ta koma baya tare da motsi iri ɗaya da akasin haka. Wannan motsi na baya ana kiransa da komawa baya.
8. Me yasa abubuwa daban-daban suke faɗuwa a daidai wannan gudu a cikin wani wuri amma suna da yanayi daban-daban?
   • amsa: A cikin sarari, saurin da ke faruwa sakamakon nauyi iri ɗaya ne ga dukkan abubuwa ba tare da la'akari da nauyinsu ba. Don haka, taro daban-daban suna faɗuwa a daidai gwargwado. Duk da haka, ƙarfin ya dogara ne akan saurin da taro. Tunda ƙarfin yana faruwa ne saboda saurin. $p=mv$, abubuwa biyu masu taro daban-daban amma gudu ɗaya zai sami lokaci daban-daban.
9. Ta yaya dokar Newton ta uku ta shafi kiyaye yanayin motsi?
   • amsa: Dokar Newton ta uku ta bayyana cewa ga kowane aiki, akwai amsawar daidai da akasin haka. Lokacin da abubuwa biyu ke hulɗa, suna yin amfani da ƙarfi iri ɗaya da na akasin haka a kan juna a lokaci guda, ma'ana suna fuskantar canje-canje iri ɗaya da na akasin haka a cikin motsi. Wannan yana haifar da jimlar motsi kafin hulɗar ta yi daidai da jimlar motsi bayan, don haka yana kiyaye motsi.
10. Me yasa ya fi sauƙi a tsayar da keke mai motsi fiye da mota mai motsi, koda kuwa suna tafiya a daidai wannan gudun?

• amsa: Duk da cewa keken da mota na iya samun saurin gudu iri ɗaya, ƙarfinsu ya bambanta saboda bambancin yawansu. Momentum ya dogara ne akan gudu da nauyi. Motar, wacce ta fi keke girma, tana da ƙarfin motsi mafi girma a daidai wannan gudun. Don haka, ana buƙatar ƙarin ƙarfin motsi (ko canjin motsi) don tsayar da motar idan aka kwatanta da keken.