Momentum - nā pilikia a me nā hoʻonā

Momentum - nā pilikia a me nā hoʻonā

1. Neʻe ka pōpō 0.5-kg ma 2 m/s. A laila ua paʻi ʻia ka pōpō me ka ikaika F e kūʻē ana i ke kuhikuhi o ka pōpō , no laila ua hoʻololi ʻia ka wikiwiki o ka pōpō i 6 m/s . Aia ka pōpō i ka pilina me kahi mea hahau no 0.01 kekona, he aha ka loli o ka momentum o ka pōpō.

ʻIke ʻia:

Ka nuipa o ka pōpō (m) = 0.5 kg

Ka wikiwiki mua (v _o ) = 2 m/s

Ka wikiwiki hope loa (vt ₎ = -6 m/s

Ka manawa (t) = 0.01 kekona

Makemake ʻia: Ka loli o ka momentum

Lōlā:

∆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. Neʻe kahi mea 100-gram ma 5 m/s. Hana ka ikaika F no 0.2 kekona e hoʻōki i ka mea. E hoʻoholo i ka nui o ka ikaika F.

ʻIke ʻia:

Ka nuipa o ka mea (m) = 100 grams = 100/1000 = 0.1 kg

Ka wikiwiki mua (v _o ) = 5 m/s

Ka wikiwiki hope loa (vt ₎ = 0

Ka manawa manawa (Δt) = 0.2 kekona

Makemake ʻia: Ka nui o ka ikaika F

Lōlā:

ʻO I = ΔP

F (Δt) = m (vt _– 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

Ka nui o ka ikaika F = 2.5 Newtons. Hōʻike ka hōʻailona Min i ke kuhikuhi o ka ikaika e kūʻē ana i ke kuhikuhi o ka mea.

3. Hāʻule manuahi kahi pōpō 100-kalama mai ke kiʻekiʻe o 20 kenimika me ka ʻole o ka wikiwiki mua a laila paʻi ka pōpō i ka papahele. Ma hope o ke kuʻi ʻana, ua hōʻike ʻia ka pōpō i luna (ʻo ka wikiwiki ma muli o ke koʻikoʻi he 10 ms ^-2 ). He aha ka loli o ka momentum o ka pōpō.

ʻIke ʻia:

Ka nuipa o ka pōpō (m) = 100 grams = 0.1 kg

Kiʻekiʻe (h) = 20 kenimika = 0.2 mika

Ka wikiwiki ma muli o ke koʻikoʻi (g) = 10 m/s ²

Ka wikiwiki o ka pōpō ma hope o ke kuʻi ʻana i ka papahele (vt ₎ = 1 m/s

Makemake ʻia: Ka loli o ka momentum

Lōlā:

Ka wikiwiki o ka pōpō ma mua o ke kuʻi ʻana (v _o )

E helu i ka wikiwiki o ka pōpō ma mua o ke kuʻi ʻana me ka hoʻohana ʻana i ka hoohalike o ka neʻe hāʻule manuahi. ʻIke ʻia: ke kiʻekiʻe o ka pōpō (h) = 0.2 mika, ka wikiwiki ma muli o ke koʻikoʻi ( g) = 10 m/s ^2. Makemake ʻia: ka wikiwiki o ka pōpō ke kuʻi i ka papahele.

v ² = 2 gh

v ² = 2 (10)(0.2) = 4

v = √4 = -2 m/s

Hōʻike ka hōʻailona Minus ua kūʻē ke kuhikuhi o ka pōpō ma mua o ke kuʻi ʻana i ke kuhikuhi o ka pōpō ma hope o ke kuʻi ʻana.

Ka loli o ka momentum o ka pōpō (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 Newton kekona

4. Ua pahū kahi mea i hoʻomaha mua ʻia i 2 mau ʻāpana me ka lakio o 3: 2. Ua kiola ʻia ka hapa nui o ka nuipa i ka wikiwiki o 20 m/s. He aha ka wikiwiki o ka ʻāpana liʻiliʻi.

ʻIke ʻia:

Ka nuipa o ka mea 1 ma mua o ka pahū = m

Ka wikiwiki o ka mea 1 ma mua o ka pahū ʻana = 0 (mea e hoʻomaha ana)

Ka nuipa o ka ʻāpana nui ma hope o ka pahū ʻana (m1 ₎ = 3m

Ka nuipa o ka ʻāpana liʻiliʻi ma hope o ka pahū ʻana (m2 ₎ = 2m

Ka wikiwiki o ka ʻāpana nui ma hope o ka pahū ʻana (v ₁ ') = 20 m/s

Makemake ʻia: Ka wikiwiki o ka ʻāpana liʻiliʻi ma hope o ka pahū ʻana (v ₂ ')

Lōlā:

ʻO ke kaulike o ke kānāwai o ka mālama ʻana i ka momentum:

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

Hōʻike ka hōʻailona minus ua kūʻē ke kuhikuhi o ka ʻāpana liʻiliʻi i ke kuhikuhi o ka ʻāpana nui.

1. He aha ka momentum?
   • pane mai: He nui vector ka Momentum e hōʻike ana i ka huahana o ka nuipa o kahi mea a me kona wikiwiki. Hōʻike ia i ke kuhikuhi a me ka nui o ka neʻe ʻana a ua hōʻailona pinepine ʻia e $p$, i wehewehe ʻia e like me $p=mv$.
2. Pehea ka ʻokoʻa o ka momentum mai ka velocity?
   • pane mai: ʻOiai ʻo ka momentum a me ka velocity he mau nui vector e pili ana i ka neʻe ʻana, ʻo ka velocity wale nō ka wehewehe ʻana i ka wikiwiki a me ke kuhikuhi o ka neʻe ʻana o kahi mea, ʻoiai ʻo ka momentum e noʻonoʻo ana i ka nuipa o ka mea a me kona wikiwiki. Hāʻawi ka Momentum i kahi ana o ka paʻakikī o ka hoʻōki ʻana i kahi mea e neʻe ana.
3. He aha ke kumumanaʻo o ka mālama ʻana i ka momentum?
   • pane mai: ʻŌlelo ke kumumanaʻo o ka mālama ʻana i ka momentum i loko o kahi ʻōnaehana i hoʻokaʻawale ʻia, pono e like ka momentum holoʻokoʻa ma mua o kahi hanana (e like me kahi ulia) me ka momentum holoʻokoʻa ma hope o ka hanana, ke ʻole nā ​​​​mana o waho e hana ma ka ʻōnaehana.
4. Pehea e pili ai ka impulse i ka momentum?
   • pane mai: ʻO ka impulse ka loli o ka momentum o kahi mea ke hoʻopili ʻia kahi ikaika ma luna o kahi manawa kikoʻī. Hāʻawi ʻia ia e ka huahana o ka ikaika a me ka manawa e hana ai, a ua like ia me ka loli o ka momentum: $\text{Pākuʻi}=F\times \Delta t=\Delta p$.
5. No ke aha e kōkua ai nā ʻeke ea i loko o nā kaʻa i ka pale ʻana i nā ʻeha i ka wā o kahi ulia?
   • pane mai: Hoʻonui nā ʻeke ea i ka manawa e hana ai ka ikaika ma luna o kahi mea noho i ka wā o kahi ulia. Hoʻemi kēia i ka ikaika awelika i ʻike ʻia e ka mea noho. Ma o ka pilina impulse-momentum, ʻo ka hoʻolaha ʻana i ka loli o ka momentum i kahi manawa lōʻihi e hōʻemi ana i ka ikaika, e kōkua ana i ka pale ʻana i nā ʻeha.
6. He aha ka ʻokoʻa ma waena o nā kuʻi elastic a me nā kuʻi inelastic e pili ana i ka momentum a me ka ikehu kinetic?
   • pane mai: I nā kuʻi elastic a me nā kuʻi inelastic, mālama ʻia ka momentum. Eia nō naʻe, i nā kuʻi elastic, mālama ʻia ka ikehu kinetic holoʻokoʻa, ʻoiai i nā kuʻi inelastic, ʻaʻole.
7. Pehea e mālama ʻia ai ka momentum i ka neʻe ʻana o ka hoʻi hope ʻana o ka pū i ka wā e kī ʻia ai?
   • pane mai: Ke kī ʻia ka pū, neʻe ka pōkā i mua me kahi momentum. No ka mālama ʻana i ka momentum i loko o ka ʻōnaehana i hoʻokaʻawale ʻia (me ka manaʻo he mea liʻiliʻi nā ikaika o waho e like me ke kū'ē ʻana o ka ea), pono ka pū e neʻe i hope me kahi momentum like a kū'ē. Ua kapa ʻia kēia neʻe hope ʻana he recoil.
8. No ke aha e hāʻule ai nā mea o nā nui like ʻole ma ka wikiwiki like i loko o kahi hakahaka akā he ʻokoʻa ko lākou mau manawa?
   • pane mai: I loko o kahi hakahaka, ua like ka wikiwiki ma muli o ke koʻikoʻi no nā mea āpau me ka nānā ʻole i ko lākou nuipaʻa. No laila, hāʻule nā ​​​​nuipaʻa like ʻole ma ka wikiwiki like. Eia nō naʻe, pili ka momentum i ka wikiwiki a me ka nuipaʻa. ʻOiai ʻo ka momentum $p=mv$, ʻelua mau mea me nā kaumaha like ʻole akā ʻo ka wikiwiki like e loaʻa ka momentum ʻokoʻa.
9. Pehea e pili ai ke kānāwai ʻekolu o Newton i ka mālama ʻana i ka momentum?
   • pane mai: ʻŌlelo ke kānāwai ʻekolu o Newton no kēlā me kēia hana, aia kahi hopena like a kū'ē. Ke launa pū nā mea ʻelua, hoʻokau lākou i nā ikaika like a kū'ē kekahi i kekahi no ka manawa like, ʻo ia hoʻi, ʻike lākou i nā loli like a kū'ē i ka momentum. ʻO ka hopena, ua like ka momentum holoʻokoʻa ma mua o ka launa pū ʻana me ka momentum holoʻokoʻa ma hope, no laila e mālama ana i ka momentum.
10. No ke aha i maʻalahi ai ka hoʻōki ʻana i kahi paikikala e neʻe ana ma mua o kahi kaʻa e neʻe ana, ʻoiai inā e holo like ana lāua?

• pane mai: ʻOiai paha he like ka wikiwiki o ke kaʻa a me ke paikikala, ʻokoʻa ko lāua momentum ma muli o ko lāua mau kaumaha like ʻole. Aia ka momentum i ka wikiwiki a me ke kaumaha. ʻOi aku ka nui o ke kaʻa ma mua o ke paikikala, ʻoi aku ka nui o ka momentum ma ka wikiwiki like. No laila, pono kahi impulse nui aʻe (a i ʻole ka loli o ka momentum) e hoʻōki i ke kaʻa i hoʻohālikelike ʻia me ke paikikala.