ke kālaikūlohea

1. Ua hoʻopuni ʻia kahi pōpō 0.2-kg, i hoʻopaʻa ʻia i ka wēlau o ke kaula ākea, i loko o kahi pōʻai o 1 mika ka radius a ʻo ka wikiwiki kiʻekiʻe loa o ka pōpō he 10 rpm. He aha ka nui o ka wikiwiki centripetal a me ka nui o ka ikaika tension?

ʻIke ʻia:

Nuipaʻa (m) = 0.2 kg

Ka laulā (r) = 1 m

Ka wikiwiki angular (ω) = 10 rev/min = 10 rev/60 s = 0.17 rev/s = (0.17)(6.28 rad)/s = 1 rad/s

Ka wikiwiki (v) = r ω = (1 m)(1 rad/s) = 1 m/s

Makemake ʻia: he _s a me Σ F

Lōlā:

(a) Ka nui o ka wikiwiki centripetal

(b) Ka nui o ka ikaika hoʻoluhi

Σ F = ma

T = ma _s

T = (0.2 kg)(1 m/s ² )

T = 0.2 kg m/s ²

T = 0.2 N

ʻAʻole maopopo

2. Ke kaʻa like nei kahi pōpō 1-kg ma ka hopena o ke kaula i loko o kahi pōʻai ʻaoʻao o 1 m ka radius. E haki ke kaula ke ʻoi aku ka nui o ke kaomi i loko o 100 N. He aha ka wikiwiki loa e hiki ai i ka pōpō ke loaʻa?

ʻIke ʻia:

Nuipaʻa (m) = 1 kg

Radius (r) = 1 mika

ʻO ka ikaika hoʻopaʻapaʻa (T) = ka ikaika centripetal ( Σ F) = 100 N

Makemake ʻia: v ka palena kiʻekiʻe loa

Lōlā:

ʻAʻole maopopo

[wpdm_package id='499′]

1. Ka nuipa a me ke kaumaha
2. Ka ikaika maʻamau
3. Ke kānāwai ʻelua o ka neʻe ʻana o Newton
4. ʻO ka ikaika pili
5. Neʻe ʻana ma luna o kahi ʻili pālahalaha me ka ʻole o ka ikaika friction
6. ʻO ka neʻe ʻana o nā kino ʻelua me ka wikiwiki like ma luna o ka ʻili pālahalaha ʻinoʻino me ka ikaika friction
7. Neʻe ʻana ma luna o kahi mokulele i hoʻokiʻekiʻe ʻia me ka ʻole o ka ikaika friction
8. Ka neʻe ʻana ma luna o ka mokulele i hoʻohaʻahaʻa ʻia me ka ikaika friction
9. Neʻe ʻana i loko o kahi elevator
10. Hoʻopili ʻia ka neʻe ʻana o nā kino e nā kaula a me nā pulleys
11. ʻElua mau kino me ka nui like o ka wikiwiki
12. Ke hoʻopuni ʻana i kahi piʻo pālahalaha - nā dinamika o ka neʻe pōʻai
13. Ke hoʻopuni ʻana i kahi piʻo panakō - nā dinamika o ka neʻe pōʻai
14. Neʻe like ʻana ma kahi pōʻai ʻākea
15. Ka ikaika centripetal i ka neʻe pōʻai like

heluhelu hou

1. He kaʻa e hoʻopuni ana i kahi piʻo kūlou. He aha ke kihi no ke alanui nona ka piʻo o ka radius he 60 mika me ka wikiwiki hoʻolālā o 20 m/s? Manaʻo ʻaʻohe kū'ē ma waena o ke kaʻa a me ke alanui.

pāʻoihana

N= ikaika maʻamau

N sin θ = ʻāpana pae o ka ikaika maʻamau

N cos θ = ʻāpana kū pololei o ka ikaika maʻamau

w = mg = ke kaumaha o ke kaʻa

Ua hoʻolālā ʻia ke alanui e hoʻopaʻa ʻia i nā kapa e hoʻopau ai i ke hilinaʻi ʻana i ka hakakā.

ʻO ka ikaika pae ʻupena, ka ʻāpana pae o ka ikaika maʻamau ( N sin θ) , pono ia e hoʻomau i ke kaʻa e neʻe i loko o kahi pōʻai a puni ke piʻo.

Koho mākou i ka axis-x ma ke ʻano he pae a me ka axis-y ma ke ʻano he kū pololei, i hiki ai i ka wikiwiki centripetal, a_R, aia ma ke kuhikuhi ʻaoʻao. Ma ke kuhikuhi ʻaoʻao, ʻo ka ikaika wale nō ka ʻāpana ʻaoʻao o ka ikaika maʻamau (N hewa θ), e pono ai e hana i ka ka wikiwiki o ke kikowaena. N sin θ = ikaika centripetal.

E hoʻopili i ke kānāwai o ka neʻe ʻana o Newton ma ke kuhikuhi kū pololei:

ʻAʻole maopopo

E hoʻopili i ke kānāwai o ka neʻe ʻana o Newton ma ke kuhikuhi ʻaoʻao:

E hoʻololi iā N ma ka hoohalike 1 i loko o N ma ka hoohalike 2 :

[wpdm_package id='497′]

1. Ka nuipa a me ke kaumaha
2. Ka ikaika maʻamau
3. Ke kānāwai ʻelua o ka neʻe ʻana o Newton
4. ʻO ka ikaika pili
5. Ka neʻe ʻana ma luna o ka ʻili ākea me ka ʻole o ka ikaika friction
6. ʻO ka neʻe ʻana o nā kino ʻelua me ka wikiwiki like ma luna o ka ʻili pālahalaha ʻinoʻino me ka ikaika friction
7. Ka neʻe ʻana ma luna o ka mokulele i hoʻohuli ʻia me ka ʻole o ka ikaika friction
8. Ka neʻe ʻana ma luna o ka mokulele i hoʻohaʻahaʻa ʻia me ka ikaika friction
9. Neʻe ʻana i loko o kahi elevator
10. Hoʻopili ʻia ka neʻe ʻana o nā kino e nā kaula a me nā pulleys
11. ʻElua mau kino me ka nui like o ka wikiwiki
12. Ke hoʻopuni ʻana i kahi piʻo pālahalaha - nā dinamika o ka neʻe pōʻai
13. Ke hoʻopuni ʻana i kahi piʻo panakō - nā dinamika o ka neʻe pōʻai
14. Neʻe like ʻana ma kahi pōʻai ʻākea
15. Ka ikaika centripetal i ka neʻe pōʻai like

heluhelu hou

1. Ke kaʻa he 2000-kg e pōʻai ana i kahi piʻo ma ke alanui pālahalaha he 150 m ka radius. ʻO ke koina o ka friction static he 0.5. E hoʻoholo i ka wikiwiki kiʻekiʻe loa i hiki i ke kaʻa ke hahai i ka piʻo a ʻaʻole e paheʻe. ʻO ka wikiwiki ma muli o ke koʻikoʻi = 10 m/s ².

ʻIke ʻia:

Nuipaʻa (m) = 2000 kg

Radius (r) = 150 mika

Ka helu o ka haʻalulu paʻa ( μs ₎ = 0.5

Kaumaha (w) = mg = (2000 kg)(10 m/s ² ) = 20,000 kg m/s ² = 20,000 N

Ka ikaika o ke kuʻi kūmau (F _s ) = μ _s N = μ _s w = (0.7)(20,000 N) = 14,000 N

Makemake ʻia : v

Lōlā:

ʻAʻole maopopo

[wpdm_package id='496′]

1. Ka nuipa a me ke kaumaha
2. Ka ikaika maʻamau
3. Ke kānāwai ʻelua o ka neʻe ʻana o Newton
4. ʻO ka ikaika pili
5. Ka neʻe ʻana ma luna o ka ʻili ākea me ka ʻole o ka ikaika friction
6. ʻO ka neʻe ʻana o nā kino ʻelua me ka wikiwiki like ma luna o ka ʻili pālahalaha ʻinoʻino me ka ikaika friction
7. Ka neʻe ʻana ma luna o ka mokulele i hoʻohuli ʻia me ka ʻole o ka ikaika friction
8. Ka neʻe ʻana ma luna o ka mokulele i hoʻohaʻahaʻa ʻia me ka ikaika friction
9. Neʻe ʻana i loko o kahi elevator
10. Hoʻopili ʻia ka neʻe ʻana o nā kino e nā kaula a me nā pulleys
11. ʻElua mau kino me ka nui like o ka wikiwiki
12. Ke hoʻopuni ʻana i kahi piʻo pālahalaha - nā dinamika o ka neʻe pōʻai
13. Ke hoʻopuni ʻana i kahi piʻo panakō - nā dinamika o ka neʻe pōʻai
14. Neʻe like ʻana ma kahi pōʻai ʻākea
15. Ka ikaika centripetal i ka neʻe pōʻai like

heluhelu hou

1. ʻElua mau nuipa m ₁ = 2 kg a me m ₂ = 5 kg ma kahi mokulele incline a ua hoʻopili ʻia lāua e ke kaula e like me ka mea i hōʻike ʻia ma ke kiʻi. ʻO ke coefficient o ka friction kinetic ma waena o m ₁ a me ka incline he 0.2 a ʻo ke coefficient o ka friction kinetic ma waena o m ₂ a me ka incline he 0.1.

(a) E hoʻoholo i ko lākou wikiwiki

(b) E hoʻoholo i ka ikaika hoʻoluhi

ʻIke ʻia:

Nuipaʻa 1 (m1 ₎ = 2 kg

Nuipaʻa 2 (m2 ₎ = 4 kg

ʻO ke koina o ka friction kinetic ma waena o m ₁ a me ka mokulele inclined (μ _k1 ) = 0.2

ʻO ke koina o ka friction kinetic ma waena o m ₂ a me ka mokulele inclined (μ _{k 2} ) = 0.1

Ka wikiwiki ma muli o ke koʻikoʻi (g) = 9.8 m/s ²

a) Ka nui a me ke kuhikuhi o ka hoʻolalelale

w ₁ = kaumaha 1 = m ₁ g = (2 kg)(9.8 m/s ² ) = 19.6 Newtons

w _1x = w ₁ sin 30 ^o = (19.6 N)(0.5) = 9.8 Newtons

w _1y = w ₁ cos 30 ^o = (19.6 N)(0.87) = 17 Newtons

N ₁ = Ka ikaika maʻamau ma m ₁ = w _1y = 17 Newtons

F _k1 = Ka ikaika o ka friction kinetic ma m ₁ = μ _k1 N ₁ = (0.2)(17 N) = 3.4 Newtons

---

w ₂ = kaumaha 2 = m ₂ g = (4 kg)(9.8 m/s ² ) = 39.2 Newtons

w _2x = w ₂ hewa 60 ^o = (39.2 N)(0.87) = 34.1 Newtons

w _2y = w ₂ cos 60 ^o = (39.2 N)(0.5) = 19.6 Newtons

N ₂ = Ka ikaika maʻamau ma m ₂ = w _2y = 19.6 Newtons

F _k2 = Ka ikaika o ka friction kinetic ma m ₂ = μ _k2 N ₂ = (0.1)(19.6 N) = 1.96 Newtons

---

Ka nui o ka hoʻolalelale ʻana:

∑ F _x = ma _x

ʻO w _2x > w _1x no laila ua like ke kuhikuhi o ka hoʻolalelale me ke kuhikuhi o w _2x.

He maikaʻi nā mana e kuhikuhi ana ma ka wikiwiki a he maikaʻi ʻole nā ​​​​mana e kuhikuhi ana ma ka ʻaoʻao kūʻē i ka wikiwiki.

w_2x - F_k2 - T₂ +T₁ - w_1x - F_k1 = (m₁ +m₂) a_x

w _2x – F _k2 – w _1x – F _k1 = (m ₁ + m ₂ ) a _x

34.1 N – 1.96 N – 9.8 N – 3.4 N = (2 kg + 4 kg) a _x

18.94 N = (6 kg) a _x

a _x = 18.94 N : 6 kg

a _x = 3.16 m/s ²

Ka nui o ka hoʻolalelale = 3.16 m/s² ^. Ke kuhikuhi o ka hoʻolalelale = ke kuhikuhi o T ₁ = ke kuhikuhi o w _2x

b) Ka nui o ka ikaika hoʻoluhi

E hoʻopili i ke kānāwai ʻelua o Newton ma ka mea 2:

w _2x – F _k2 – T ₂ = m ₂ a _x

34.1 N – 1.96 N – T ₂ = (4 kg)(3.16 m/s ² )

32.14 N – T ₂ = 12.64 N

T ₂ = 32.14 N – 12.64 N = 19.5 Newtons

ʻO ka ikaika hoʻoluhi = T = T ₁ = T ₂ = 19.5 Newtons

ʻAʻole maopopo

2. m ₁ = 4 kg, m ₂ = 2 kg. E hoʻoholo i (a) ka nui a me ke kuhikuhi o ka wikiwiki (b) Ka nui o ka ikaika ume e hoʻopili ai iā m ₁ a me m ₂ (c) ka nui o ka ikaika ume e hoʻopili ai i ka pulley a me ka hale.

pāʻoihana

w ₁ = m ₁ g = (4 kg)(9.8 m/s ² ) = 39.2 Newtons

w ₂ = m ₂ g = (2 kg)(9.8 m/s ² ) = 19.6 Newtons

a) Ka nui a me ke kuhikuhi o ka hoʻolalelale

∑ F _y = ma _y

ʻO w ₁ > w ₂ no laila ua like ke kuhikuhi o ka mea me ke kuhikuhi o ke kaumaha 1 ( w ₁ ) . He maikaʻi nā ikaika i loaʻa ke kuhikuhi like me ka wikiwiki a he maikaʻi ʻole nā ​​​​ikaika i loaʻa ke kuhikuhi kū'ē me ka wikiwiki.

w ₁ – T ₁ + T ₂ – w ₂ = (m ₁ + m ₂ ) a _y

w ₁ – w ₂ = (m ₁ + m ₂ ) a _y

39.2 N – 19.6 N = (4 kg + 2 kg) i kēlā me kēia _makahiki

19.6 N = (6 kg) a _y

a _y = 19.6 N : 6 kg

a _y = 3.26 m/s ²

Ka nui o ka hoʻolalelale = 3.26 m/s² ^. Ke kuhikuhi o ka hoʻolalelale = ke kuhikuhi o _w1.

b) Ka nui o ka ikaika ume e hoʻopili ai iā m ₁ a me m ₂

E hoʻopili i ke kānāwai ʻelua o Newton ma m ₂ :

∑ F _y = ma _y

w ₁ – T ₁ = m ₁ a _y

39.2 N – T ₁ = (4 kg)( 3.26 m/s ² )

39.2 N – T ₁ = 13.04 N

T ₁ = 39.2 N – 13.04 N

T ₁ = 26.16 Newton

Ka nui o ka ikaika ume e hoʻopili ai i nā mea = T = T ₁ = T ₂ = 26.16 Newtons

c) Ka nui o ka ikaika ume e hoʻohui ai i ka pulley a me ka hale.

Ua hoʻomaha ʻo Pulley:

∑ F _y = ma _y —— a _y = 0

∑ F _y = 0

He maikaʻi nā mana i luna, he maikaʻi ʻole nā ​​mana i lalo:

T ₃ – T ₁ – T ₂ = 0

T3 = _T1 + _T2

Ua like ka nui o T ₁ a me T ₂ , T ₁ = T ₂ = T = 26.16 N :

T ₃ = 2T = 2(26.16 N) = 52.32 Newtons

ʻAʻole maopopo

3. ʻO ka poloka 1 (m ₁ = 10 kg) a me ka poloka 2 (m ₂ = 15 kg) i hoʻopili ʻia e ke kaula ma luna o ka pulley frictionless. ʻO ke koina o ka friction static ma waena o ka poloka 2 me ka incline = 0.6. ʻO ke koina o ka friction kinetic ma waena o ka poloka 2 me ka incline = 0.42. E hoʻoholo (a) ʻO ka nui o ka ikaika liʻiliʻi F i hoʻokau ʻia ma luna o nā mea i wikiwiki ai nā mea i luna (b) E hoʻoholo i ka nui o ka ikaika tension.

pāʻoihana

w ₁ = Ke kaumaha o ka poloka 1 = m ₁ g = (10 kg)(9.8 m/s ² ) = 98 Newtons

w ₂ = Ke kaumaha o ka poloka 2 = m ₂ g = (15 kg)(9.8 m/s ² ) = 147 Newtons

w _2y = w ₂ cos 30 ^o = (147 N)(0.87) = 127.89 Newtons

w _2x = w ₂ hewa 30 ^o = (147 N)(0.5) = 73.5 Newtons

N ₂ = Ka ikaika maʻamau ma ka poloka 2 = w _2y = 127.89 Newtons

F _k2 = Ka ikaika o ka friction kinetic ma ka poloka 2 = μ _k2 N ₂ = (0.42)(127.89 N) = 53.7 Newtons

F _s2 = Ka ikaika o ka haʻalulu paʻa ma ka poloka 2 = μ _s2 N ₂ = (0.6)(127.89 N) = 76.7 Newtons

a) ʻO ka nui o ka ikaika liʻiliʻi loa F i hoʻokau ʻia ma luna o nā mea i wikiwiki ai nā mea i luna

∑ F _x = ma _x —— a _x = 0

∑ F _x = 0

He maikaʻi nā mana i luna a me nā mana ʻākau, he maikaʻi ʻole nā ​​​​mana i lalo a me nā mana hema.

F – F _k2 – w _2x – w ₁ – T ₂ + T ₁ = 0

F – F _k2 – w _2x – w ₁ = 0

F = F _k2 + w _2x + w ₁

F = 53.7 N + 73.5 N + 98 N

F = 225.2 Newton

b) Ka nui o ka ikaika hoʻoluhi

E hoʻopili i ke kānāwai o ka neʻe ʻana o Newton ma ka poloka 1:

∑ F _y = ma _y —— a _y = 0

∑ F _y = 0

T ₁ – w ₁ = 0

T ₁ = w ₁ = 98 Newton

E hoʻopili i ke kānāwai o ka neʻe ʻana o Newton ma ka poloka 2:

F – F _k2 – w _2x – T ₂ = 0

T ₂ = F – F _k2 – w _2x

T ₂ = 225.2 N – 53.7 N – 73.5 N

T ₂ = 98 Newton

Ka nui o ka ikaika hoʻoluhi = T ₁ = T ₂ = T = 98 Newtons

ʻAʻole maopopo

4. Aia ka poloka 1 (m ₁ = 16 kg) ma luna o kahi ʻili ākea a aia ka poloka 2 (m ₂ = 12 kg) ma luna o kahi mokulele hilig laumania, i hoʻopili ʻia e ke kaula e hele ana ma luna o kahi pulley liʻiliʻi, ʻaʻohe friction. Aia ka poloka 3 (m ₃ = 5 kg) ma luna o ka poloka 2. ʻO ke koina o ka friction kinetic ma waena o ka poloka 2 a me ka ʻili ākea he 0,4. ʻO ke koina o ka friction static ma waena o ka poloka 2 me ka poloka 3 he 0,3.

(a) Ke hoʻokuʻu ʻia ka ʻōnaehana mai ka hoʻomaha, e paheʻe pū ana ka poloka 3 a me ka poloka 2?

(b) Inā aia ka poloka 3, he aha ka wikiwiki o ka poloka 1 a me ka poloka 2?

Lōlā:

a) Ke hoʻokuʻu ʻia ka ʻōnaehana mai ka hoʻomaha, e paheʻe pū ana ka poloka 3 a me ka poloka 2?

w ₁ = Ke kaumaha o ka poloka 1 = m ₁ g = (16 kg)(9.8 m/s ² ) = 156.8 Newtons

w _1x = w ₁ sin 60 ^o = (156.8 N)(0.87) = 136.4 Newtons

w _1y = w ₁ cos 60 ^o = (156.8 N)(0.5) = 78.4 Newtons

N ₁ = Ka ikaika maʻamau i hoʻokau ʻia ma ka poloka 1 e ka mokulele inclined = w _1y = 78.4 Newtons

w ₃ = Ke kaumaha o ka poloka 3 = m ₃ g = (5 kg)(9.8 m/s ² ) = 49 Newtons

N ₂₃ = Ka ikaika maʻamau i hoʻokau ʻia ma ka poloka 3 e ka poloka 2 = w ₃ = 49 Newtons

N ₃₂ = Ka ikaika maʻamau i hoʻokau ʻia ma ka poloka 2 e ka poloka 3 = N ₂₃ = w ₃ = 49 Newtons

(ʻO N ₂₃ a me N ₃₂ nā hui hana-pane )

F _s23 = Ka ikaika o ka haʻalulu paʻa i hoʻokau ʻia ma ka poloka 3 e ka poloka 2 = μ _s N ₂₃ = (0.3)(49 N) = 14.7 Newtons

F _s32 = Ka ikaika o ka haʻalulu paʻa i hoʻokau ʻia ma ka poloka 2 e ka poloka 3 = F _{s 23} = 14.7 Newtons

(ʻO F _s23 a me F _s32 he mau hui hana-pane )

w ₂ = Ke kaumaha o ka poloka 2 = m ₂ g = (12 kg)(9.8 m/s ² ) = 117.6 Newtons

N ₂ = Ka ikaika maʻamau i hoʻokau ʻia ma luna o ka mea 2 e ka ʻili ākea = w ₂ + N ₃₂ = 117.6 Newtons + 49

Newton = 166.6 Newton

F _k2 = Ka ikaika o ka friction kinetic ma ka poloka 2 = μ _k N ₂ = (0.4)(166.6 N) = 66.64 Newtons

E hoʻopili i ke kānāwai o ka neʻe ʻana o Newton ma ka poloka 3:

∑ F _x = ma _x

F _s23 = m ₃ a _x

—–> F_s23 = μ_s N₂₃ = μ_s w₃ = μ_s m₃ g

μ _s m ₃ g = m ₃ a _x

μ _s g = a _x

a _x = (0.3)(9.8 m/s ² ) = 2.94 m/s ²

ʻO ka wikiwiki kiʻekiʻe loa o ka poloka 3 i hiki ai i ka poloka 3 a me ka poloka 2 ke paheʻe pū he 2.94 m/ ^s².

I kēia manawa, ke helu nei mākou i ka nui o ka wikiwiki o ka ʻōnaehana ma hope o ka hoʻokuʻu ʻia ʻana mai ka hoʻomaha.

ʻO ke kuhikuhi o ka neʻe ʻana o ka poloka = ke kuhikuhi o ka wikiwiki o ka poloka = ke kuhikuhi o T ₂ = ke kuhikuhi o w _1x.

∑ F _x = ma _x

w_1x - T₁ +T₂ - F_k2 - F_s32 +F_s23 = (m₁ +m₂ +m₃) a_x

w _1x – F _k2 = (m ₁ + m ₂ + m ₃ ) a _x

136.4 N – 66.64 N = (16 kg + 12 kg + 5 kg) a _x

69.76 N = (33 kg) a _x

a _x = 2.11 m/s ²

He maikaʻi ʻo a _x , ʻo ia hoʻi ke kuhikuhi o ka neʻe ʻana o ka poloka a i ʻole ke kuhikuhi o ka hoʻolalelale ʻana ua like ia me ke kuhikuhi o T ₂ a i ʻole ke kuhikuhi o w _1x.

ʻO ka nui o ka hoʻolalelale ʻana he 2.11 m/s² ^, haʻahaʻa ma mua o 2.94 m/s² ^no laila hiki iā mākou ke hoʻoholo e paheʻe pū ana ka poloka 3 a me ka poloka 2 ma hope o ka hoʻokuʻu ʻia ʻana mai ka hoʻomaha.

b) Ka nui o ka wikiwiki o ka poloka 1 a me ka poloka 2

∑ F _x = ma _x

w _1x – F _k2 = (m ₁ + m ₂ ) a _x

—–> F_k2 = μ_k N₂ = μ_k w₂ = μ_k m₂ g = (0.4)(12 kg)(9.8 m/s²) = 47.04 Newton

136.4 N – 47.04 N = (16 kg + 12 kg) a _x

89.36 N = (28 kg) a _x

a _x = 89.36 N : 28 kg = 3.19 m/s ²

[wpdm_package id='493′]

1. Ka nuipa a me ke kaumaha
2. Ka ikaika maʻamau
3. Ke kānāwai ʻelua o ka neʻe ʻana o Newton
4. ʻO ka ikaika pili
5. Ka neʻe ʻana ma luna o ka ʻili ākea me ka ʻole o ka ikaika friction
6. ʻO ka neʻe ʻana o nā kino ʻelua me ka wikiwiki like ma luna o ka ʻili pālahalaha ʻinoʻino me ka ikaika friction
7. Ka neʻe ʻana ma luna o ka mokulele i hoʻohuli ʻia me ka ʻole o ka ikaika friction
8. Ka neʻe ʻana ma luna o ka mokulele i hoʻohaʻahaʻa ʻia me ka ikaika friction
9. Neʻe ʻana i loko o kahi elevator
10. Hoʻopili ʻia ka neʻe ʻana o nā kino e nā kaula a me nā pulleys
11. ʻElua mau kino me ka nui like o ka wikiwiki
12. Ke hoʻopuni ʻana i kahi piʻo pālahalaha - nā dinamika o ka neʻe pōʻai
13. Ke hoʻopuni ʻana i kahi piʻo panakō - nā dinamika o ka neʻe pōʻai
14. Neʻe like ʻana ma kahi pōʻai ʻākea
15. Ka ikaika centripetal i ka neʻe pōʻai like

heluhelu hou

1. Aia kahi poloka 2-kg ma luna o kahi mokulele hilig ʻino ma ke kihi 37 ^o i ka pae. E hoʻoholo i ka nui o ka ikaika waho i hoʻokau ʻia ma luna o ka poloka, i ʻole e paheʻe ka poloka i lalo o ka mokulele. (sin 37 ^o = 0.6, cos 37 ^o = 0.8, g = 10 ms ^-2 , µ _k = 0.2)

ʻIke ʻia:

Nuipaʻa (m) = 2 kg

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

Kaumaha o ka poloka (w) = mg = (2)(10) = 20 Newtons

Sin 37 ^o = 0.6

Cos 37 ^o = 0.8

Ka helu o ka haʻalulu kinetic (µ _k ) = 0.2

ʻO ka ʻāpana y o ke kaumaha (w _y ) = w cos 37 ^o = (20)(0.8) = 16 Newtons

ʻO ka ʻāpana x o ke kaumaha (w _x ) = w sin θ = (20)(sin 37) = (20)(0.6) = 12 Newtons

ka ikaika maʻamau (N) = w _y = 16 Newtons

Makemake ʻia : ʻO ka ikaika o waho (F)

Hoʻonā :

w_x = 12 Newton

ʻO ka ikaika o ka friction kinetic (f _k ) = µ _k N = (0.1)(16) = 1.6 Newtons

ʻO ka nui o ka ikaika waho F i hoʻokau ʻia ma luna o ka poloka :

F + _fk – wx ₌ 0

F = w _x – f _k

F = 12 – 1.6

F = 10.4 Newton

ʻOi aku ka ikaika waho F ma mua o 10.4 Newtons.

ʻAʻole maopopo

2. Ke kaumaha o kahi poloka = 2 kg, ke koina o ka friction static µs ₌ 0.4 a me θ = 45 ^o . E hoʻoholo i ka nui o ka ikaika F i hoʻomaka ai ka poloka e paheʻe i luna.

ʻIke ʻia:

ʻO ke koina o ka haʻalulu paʻa (µs ₎ = 0.4

Kihi (θ) = 45 ^o

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

Ka nuipa o ka poloka (m) = 2 kilokani

Kaumaha o ka poloka (w) = mg = (2 kg)(10 m/s ² ) = 20 kg m/s ² = 20 Newtons

ʻO ka ʻāpana x o ke kaumaha (w _x ) = w sin θ = (20)(sin 45) = (20)(0.5√2) = 10√2 Newtons

ʻO ka ʻāpana y o ke kaumaha (w _y ) = w cos θ = (20)(cos 45) = (20)(0.5√2) = 10√2 Newtons

Makemake ʻia : Ka nui o ka ikaika F

Lōlā:

Hoʻomaka ka poloka e paheʻe i luna, inā F ≥ w_x + f_s.

ʻO ka ʻāpana-x o ke kaumaha:

w _x = 10√2 Newton

ka ʻāpana-y o ke kaumaha :

w _y = 10√2 Newton

Ka ikaika maʻamau :

N = w _y = 10√2 Newton

Ka ikaika o ka haʻalulu paʻa :

f _s = µ _s N = (0,4)(10√2) = 4√2

ʻO ka nui o ka ikaika F i hoʻomaka ai ka poloka e paheʻe i luna :

F ≥ w _x + f _s

F ≥ 10√2 + 4 √2

F ≥ 14√2 Newton

[wpdm_package id='492′]

1. Nā ʻāpana i ke kaulike hoʻokahi-dimensional
2. Nā ʻāpana i ke kaulike ʻelua-dimensional
3. Ke kaulike o nā kino i hoʻopili ʻia e nā kaula a me nā pulleys
4. Ke kaulike o nā kino ma ka mokulele inclined

heluhelu hou

1. Aia kahi pahu me ke kaumaha he 5 kg ma luna o kahi mokulele hilig ma kahi kihi 30 ^o . Kākoʻo ʻia ka pahu e ke kaula. E hoʻoholo i ka ikaika ume (T) a me ka ikaika maʻamau (N)!

pāʻoihana

ΣF_x = 0

T – w sin 30 ^o = 0

T = w sin 30 ^o

T = (5 kg)(9.8 m/s² ⁾ sin 30 ^o

T = (49)(0.5)

T = 24.5 Newton

∑ F _y = 0

N – w cos 30 ^o = 0

N = w cos 30 ^o

N = (49)(0.87)

N = 43 Newton

ʻAʻole maopopo

2. ʻElua mau mea o ke kaumaha m ₁ = m ₂ = 2 kg, i hoʻopili ʻia e ke kaula nui ʻole ma luna o kahi pulley frictionless. E huli i nā ikaika tension T ₁ a me T ₂.

pāʻoihana

(a) Kiʻikuhi kino kūʻokoʻa no ka mea 1 (b) Kiʻikuhi kino kūʻokoʻa no ka mea 2

E hoʻopili i ke kānāwai mua o Newton i ka mea 1:

∑ F _y = 0

T ₁ – w ₁ = 0

T ₁ = w ₁ = m ₁ g = (2 kg)(9.8 m/s ² ) = 19.6 N

E hoʻopili i ke kānāwai mua o Newton i ka mea 2:

∑ F _y = 0

T ₂ – w ₂ = 0

T ₂ = w ₂ = m ₂ g = (2 kg)(9.8 m/s ² ) = 19.6 N

T ₁ = T ₂ = 19.6 N.

ʻAʻole maopopo

3. Hoʻopaʻa ʻia kahi mea kaumaha w _A = 30 N a me kahi mea kaumaha w _{B = 40 N, e ke kaula māmā e hele ana ma luna o kahi pulley frictionless o ka nuipa liʻiliʻi. E hoʻoholo i ke koina o ka} friction static kiʻekiʻe loa ma waena o w _B a me ka ʻili i hoʻohaʻahaʻa ʻia, inā e hoʻomaha ana ka ʻōnaehana.

pāʻoihana

(a) Kiʻikuhi kino kūʻokoʻa no ka mea w _A (b) Kiʻikuhi kino kūʻokoʻa no ka mea w _B

E hoʻopili i ke kānāwai mua o Newton i ka mea w _A ma ke kuhikuhi kū pololei (y):

∑ F _y = 0 (ʻaʻohe wikiwiki i ke kuhikuhi kū pololei)

T – w _A = 0

T = w _A = 30 Newton

E hoʻopili i ke kānāwai mua o Newton i ka mea w _B ma ke kuhikuhi kū pololei (y) :

∑ F _y = 0

N – w _B cos 45 ^o = 0

N = w _B cos 45 ^o = (40)(0.7) = 28 Newtons

E hoʻopili i ke kānāwai mua o Newton i ka mea w _B ma ke kuhikuhi ʻaoʻao (x):

∑ F _x = 0

F _k + w _B sin 45 ^o – T = 0

μ _s N + w _B sin 45 ^o – T = 0

μ _s (28) + (40)(0.7) – 30 = 0

μ _s (28) + 28 – 30 = 0

μ _s (28) = 30 – 28

μs (28) = ₂

μ _s = 2 / 28

μs = _0.07

ʻO ke koina o ka haʻalulu paʻa kiʻekiʻe loa ma waena o w _B a me ka ʻili i hoʻokiʻekiʻe ʻia = 0.07.

[wpdm_package id='490′]

1. Nā ʻāpana i ke kaulike hoʻokahi-dimensional
2. Nā ʻāpana i ke kaulike ʻelua-dimensional
3. Ke kaulike o nā kino i hoʻopili ʻia e nā kaula a me nā pulleys
4. Ke kaulike o nā kino ma ka mokulele inclined

heluhelu hou

1. E huli i nā ikaika umekaumaha T1 _, T2 _, a me T3 _. E hoʻowahāwahā i ke kaumaha o ke kaula.

pāʻoihana

(a) Kiʻikuhi kino kūʻokoʻa no ka mea (b) Kiʻikuhi kino kūʻokoʻa no ke kaula

E hoʻopili i ke kānāwai mua o Newton ma luna o ka mea:

ΣF _y = 0

T ₁ – w = 0

T ₁ = w = mg

T ₁ = (5 kg)(9.8 m/s ² )

T ₁ = 49 kg m/s ²

T ₁ = 49 N

E hoʻopili i ke kānāwai mua o Newton ma ke kaula:

∑ F _x = 0

T _3x – T _2x = 0

T ₃ cos 30 ^o – T ₂ cos 40 ^o = 0

0.87 T ₃ – 0.77 T ₂ = 0

0.87 T ₃ = 0.77 T ₂

T ₂ = 0.87 T ₃ / 0.77 = 1.1 T ₃ ———- Kaulike 1

ʻAʻole maopopo

-

∑ F _y = 0

T _3y + T _2y – T _1y = 0

T ₃ hewa 30 ^o + T ₂ hewa 40 ^o – T ₁ = 0

0.5 T ₃ + 0.64 T ₂ – 49 N = 0 ———- Kaulike 2

Ke pani nei iā T ₂ i loko o ka hoohalike 2 i loko o ka hoohalike 2:

0.5 T₂ ₊ 0.64 (1.1 T₂ ₎ – 49 N = 0

0.5 T ₃ + 0.70 T ₃ – 49 = 0

1.2 T ₃ – 49 = 0

1.2 T ₃ = 49

T ₃ = 49 / 1.2

T ₃ = 41 N

---

T ₂ = 1.1 T ₃

T ₂ = (1.1)(40.8 N)

T ₂ = 45 N

[wpdm_package id='488′]

1. Nā ʻāpana i ke kaulike hoʻokahi-dimensional
2. Nā ʻāpana i ke kaulike ʻelua-dimensional
3. Ke kaulike o nā kino i hoʻopili ʻia e nā kaula a me nā pulleys
4. Ke kaulike o nā kino ma ka mokulele inclined

heluhelu hou

^{1. Ke kaumaha o kahi mea, m = 10 kg, i kākoʻo ʻia e ke kaula. E huli i ke kaumaha ma ke kaula!} g = 10 m/s ²

ʻIke ʻia:

Nuipaʻa (m) = 10 kg

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

Makemake ʻia: Ka ikaika hoʻoluhi (T)

Lōlā:

ΣF _y = 0

T – w = 0

T = w

T = mg

T = (10 kg)(10 m/s ² ) = 100 kg m/s ²

T = 100 Newton

ʻAʻole maopopo

2. ʻO ke kaumaha o ka mea he 10 kg. E huli i ke kaomi ma ke kaula….. Ka wikiwiki ma muli o ke koʻikoʻi = 10 m/ ^s2.

pāʻoihana

ʻIke ʻia:

Nuipaʻa (m) = 10 kg

Ka wikiwiki ma muli o ke koʻikoʻi (g) = 10 m/ ^s².

Makemake ʻia: Ka ikaika hoʻoluhi (T)

Lōlā:

^{w = kaumaha = mg = (10 kg)(10 m/s2)}) = 100 kg m/s²

T ₁ = ka ikaika hoʻoluhi 1

_{T 1x} = ka ʻāpana-x o ka ikaika hoʻoluhi 1 = T ₁ cos 45 ^o = 0.7 T ₁

_{T 1y} = ka ʻāpana-y o ka ikaika hoʻoluhi 2 = T ₁ sin 45 ^o = 0.7 T ₁

T ₂ = ka ikaika hoʻoluhi 2

_{T 2x} = ka ʻāpana-x o ka ikaika hoʻoluhi 2 = T ₂ cos 45 ^o = 0.7 T ₂

_{T 2y} = ka ʻāpana-y o ka ikaika hoʻoluhi 2 = T ₂ sin 45 ^o = 0.7 T ₂

ʻO ke kūlana kaulike ΣF = 0.

axis y:

ΣF _y = 0

T _1y + T _2y – w = 0

0.7T ₁ + 0.7T ₂ – 100 = 0

0.7T ₁ + 0.7T ₂ = 100 —– kaulike 1

ʻaoʻao x:

ΣF _x = 0

T _2x – T _1x = 0

0.7T ₂ – 0.7T ₁ = 0

0.7T ₂ = 0.7T ₁

T ₂ = T ₁ —– kaulike 2

E hoʻoholo i ka nui o T ₁ :

0.7T ₁ + 0.7T ₁ = 100

1.4T ₁ = 100

T ₁ = 100 / 1.4

T ₁ = 71.4 Newton

T ₁ = T ₂ no laila ʻo T ₂ = 71.4 Newtons

[wpdm_package id='486′]

1. Nā ʻāpana i ke kaulike hoʻokahi-dimensional
2. Nā ʻāpana i ke kaulike ʻelua-dimensional
3. Ke kaulike o nā kino i hoʻopili ʻia e nā kaula a me nā pulleys
4. Ke kaulike o nā kino ma ka mokulele inclined

heluhelu hou

1. Ua hoʻopili ʻia ʻelua mau pahu e ke kaula e holo ana ma luna o kahi pulley. E hoʻowahāwahā i ke kaumaha o ke kaula a me ka pulley a me kekahi friction i loko o ka pulley. ʻO ke kaumaha o ka pahu 1 = 2 kg, ke kaumaha o ka pahu 2 = 3 kg, ka wikiwiki ma muli o ke umekaumaha = 10 m/s ^2. E huli (a) Ka wikiwiki o ka ʻōnaehana (b) Ke tension i loko o ke kaula!

pāʻoihana

ʻIke ʻia:

Ka nuipa o ka pahu 1 (m1 ₎ = 2 kg

Ka nuipa o ka pahu 2 (m2 ₎ = 3 kg

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

Kaumaha o ka pahu 1 (w ₁ ) = m ₁ g = (2)(10) = 20 Newtons

Kaumaha o ka pahu 2 (w ₂ ) = m ₂ g = (3)(10) = 30 Newtons

Lōlā:

(a) ka nui a me ke kuhikuhi o ka hoʻolalelale ʻana

w ₂ > w ₁ no laila e wikiwiki ana ka pahu 2 i lalo a e wikiwiki ana ka pahu 1 i luna.

ʻO nā mana i loaʻa ke kuhikuhi like me ka wikiwiki (w ₂ a me T ₁ ), he maikaʻi ko lākou hōʻailona. ʻO nā mana i kū'ē i ke kuhikuhi i ka wikiwiki (T ₂ a me w ₁ ), he maikaʻi ʻole ko lākou hōʻailona.

∑ F = ma

w₂ - T₂ +T₁ - w₁ = (m₁ +m₂) he ——-> T₁ =T₂ =T

w ₂ – T + T – w ₁ = (m ₁ + m ₂ ) a

w ₂ – w ₁ = (m ₁ + m ₂ ) a

30 – 20 = (2 + 3) a

10 = 5 a

a = 10 / 5

a = 2 m/s ²

ʻO ka nui o ka hoʻolalelale ʻana he 2 m/ ^s².

(b) Ka ikaika hoʻoluhi

ʻO ka pahu 2:

ʻElua mau mana e hana ana ma ka pahu 2: ʻo ka mua, ke kaumaha o ka pahu 2 (w ₂ ), e kuhikuhi ana i lalo no laila he maikaʻi. ʻO ka lua, ʻo ka ikaika hoʻoluhi i hoʻokau ʻia ma ka pahu 2 (T ₂ ), e kuhikuhi ana i luna no laila he maikaʻi ʻole. E hoʻopili i ke kānāwai ʻelua o ka neʻe ʻana o Newton.

∑ F = ma

w ₂ – T ₂ = m ₂ a

30 – T ₂ = (3)(2)

30 – T ₂ = 6

T ₂ = 30 – 6

T ₂ = 24 Newton

Pahu 1:

ʻElua mau mana e hana ana ma ka pahu 1. ʻO ka mua , ke kaumaha o ka pahu 1 (w ₁ ), e kuhikuhi ana i lalo no laila he maikaʻi ʻole. ʻO ka lua , ʻo ka ikaika hoʻoluhi i hoʻokau ʻia ma ka pahu 1 (T ₁ ) e kuhikuhi ana i luna no laila he maikaʻi. E hoʻopili i ke kānāwai ʻelua o ka neʻe ʻana o Newton:

∑ F = ma

T ₁ – w ₁ = m ₁ a

T ₁ – 20 = (2)(2)

T ₁ – 20 = 4

T ₁ = 20 + 4

T ₁ = 24 Newton

Ka nui o ka ikaika hoʻoluhi = T ₁ = T ₂ = T = 24 Newtons

ʻAʻole maopopo

2. He mea ma luna o kahi ʻili pālahalaha ʻāwiliwili. Nui o ka mea 1 = 2 kg, nui o ka mea 2 = 4 kg, wikiwiki ma muli o ke koʻikoʻi = 10 m/s ² , coefficient o ka friction static = 0.4, coefficient o ka friction kinetic = 0.3. Ke hoʻomaha nei ka ʻōnaehana a i ʻole ke hoʻolalelale ʻia? Inā hoʻolalelale ʻia ka ʻōnaehana, e ʻimi i ka nui a me ke kuhikuhi o ka wikiwiki o ka ʻōnaehana!

pāʻoihana

ʻIke ʻia:

Ka nuipa o ka mea 1 (m1 ₎ = 2 kg

Ka nuipa o ka mea 2 (m2 ₎ = 4 kg

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

ʻO ke koina o ka haʻalulu paʻa ( μs ₎ = 0.4

ʻO ke koina o ka friction kinetic ( μk ₎ = 0.3

Kaumaha o ka mea 1 (w ₁ ) = m ₁ g = (2)(10) = 20 Newtons

Kaumaha o ka mea 2 (w ₂ ) = m ₂ g = (4)(10) = 40 Newtons

Ka ikaika maʻamau i hoʻokau ʻia ma luna o ka mea 1 (N) = w ₁ = 20 Newtons

Ka ikaika o ka haʻalulu paʻa i hoʻokau ʻia ma luna o ka mea 1 (f _s ) = μ _s N = (0.4)(20) = 8 Newtons

Ka ikaika o ka friction kinetic i hoʻokau ʻia ma luna o ka mea 1 (f _k ) = μ _k N = (0.3)(20) = 6 Newtons

Makemake ʻia: hoʻolalelale (a)

Lōlā:

w ₂ > f _s (40 Newton > 8 Newton) no laila ua hoʻolalelale ʻia ka mea 2 i lalo a ua hoʻolalelale ʻia ka mea 1 i ka ʻākau. ʻO ka ikaika friction e hana ana ma luna o nā mea 1 ʻo ia ka ikaika o ka friction kinetic (f _k ). E hoʻopili i ke kānāwai neʻe ʻelua o Newton:

∑ F = ma

w ₂ – ka = (m ₁ + m ₂ ) a

40 – 6 = (2 + 4) a

34 = 6 a

a = 34 / 6 = 17 / 3

a = 5.7 m/s ²

Ka nui o ka hoʻolalelale = 5.7 m/s ²

[wpdm_package id='484′]

1. Ka nuipa a me ke kaumaha
2. Ka ikaika maʻamau
3. Ke kānāwai ʻelua o ka neʻe ʻana o Newton
4. ʻO ka ikaika pili
5. Neʻe ma luna o ka ʻili moe me ka ʻole o ka ikaika friction
6. ʻO ka neʻe ʻana o nā kino ʻelua me ka wikiwiki like ma luna o ka ʻili pālahalaha ʻinoʻino me ka ikaika friction
7. Ka neʻe ʻana ma luna o ka mokulele i hoʻohuli ʻia me ka ʻole o ka ikaika friction
8. Ka neʻe ʻana ma luna o ka mokulele i hoʻohaʻahaʻa ʻia me ka ikaika friction
9. Neʻe ʻana i loko o kahi elevator
10. Hoʻopili ʻia ka neʻe ʻana o nā kino e nā kaula a me nā pulleys
11. ʻElua mau kino me ka nui like o ka wikiwiki
12. Ke hoʻopuni ʻana i kahi piʻo pālahalaha - nā dinamika o ka neʻe pōʻai
13. Ke hoʻopuni ʻana i kahi piʻo panakō - nā dinamika o ka neʻe pōʻai
14. Neʻe like ʻana ma kahi pōʻai ʻākea
15. Ka ikaika centripetal i ka neʻe pōʻai like

heluhelu hou

1. He kanaka 50-kg i loko o kahi eleweka. ʻO ka wikiwiki ma muli o ke koʻikoʻi = 10 m/s ^2. E hoʻoholo i ka ikaika maʻamau i hoʻokau ʻia ma luna o ka mea e ka eleweka, inā:

(a) ua hoʻomaha ka elevator

(b) ke neʻe nei ka elevator i lalo ma ka wikiwiki mau

(c) ua hoʻolalelale ʻia ka elevator i luna ma kahi hoʻolalelale mau 5 /s ²

(d) ua hoʻolalelale ʻia ka elevator i lalo ma kahi mau 5 m/s ²

(e) ka elevator i ka hāʻule manuahi

pāʻoihana

ʻIke ʻia:

Ka nuipa o ke kanaka (m) = 50 kg

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

Kaumaha (w) = mg = (50)(10) = 500 Newtons

Makemake ʻia: Ka ikaika maʻamau (N)

Lōlā:

(a) ua hoʻomaha ka elevator

Ua hoʻomaha ka elevator no laila ʻaʻohe wikiwiki (a = 0)

Koho mākou i ke kuhikuhi i luna ma ke kuhikuhi maikaʻi a me ke kuhikuhi i lalo ma ke kuhikuhi maikaʻi ʻole.

Σ F = ma

N – w = 0

N = w

N = 500 Newton

(b) ke neʻe nei ka elevator i lalo ma ka wikiwiki mau

Ka wikiwiki mau no laila ʻaʻohe wikiwiki (a = 0)

Koho mākou i ke kuhikuhi i luna ma ke kuhikuhi maikaʻi a me ke kuhikuhi i lalo ma ke kuhikuhi maikaʻi ʻole.

Σ F = ma

N – w = 0

N = w

N = 500 Newton

(c) ua hoʻolalelale ʻia ka elevator i luna ma kahi mau 5 m/s ²

Piʻi ke kuhikuhi o ka hoʻolalelale ʻana, no laila koho mākou i ke kuhikuhi maikaʻi i luna.

N – w = ma

N = w + ma

N = 500 + (50)(5)

N = 500 + 250

N = 750 Newton

Manaʻo ke kanaka i ka papahele e neʻe ikaika ana i luna ma mua o ka wā e kū ana ka elevator a i ʻole e neʻe ana me ka wikiwiki mau.

Inā kū ke kanaka ma luna o kahi unahi, heluhelu ke unahi i ka nui o ka ikaika i lalo i hoʻokau ʻia e ke kanaka ma ke unahi. Ma ke kānāwai ʻekolu o Newton, ua like kēia me ka nui o ka ikaika maʻamau i luna i hoʻokau ʻia e ke unahi ma luna o ke kanaka.

(d) ua hoʻolalelale ʻia ka elevator i lalo ma kahi mau 5 m/s ²

I lalo ke kuhikuhi o ka hoʻolalelale ʻana, no laila koho mākou i ke kuhikuhi maikaʻi i lalo.

w – N = ma

N = w – ma

N = 500 – (50)(5)

N = 500 – 250

N = 250 Newton

He 250 N ke kaumaha o ke kanaka, ʻoi aku ka emi ma mua o ke kaumaha maoli w = 500 N.

(e) ka elevator i ka hāʻule manuahi

ʻO ke ʻano o ka hāʻule manuahi, ua like ka wikiwiki o ka elevator me ka wikiwiki ma muli o ke koʻikoʻi. ʻO ka nui o ka wikiwiki ma muli o ke koʻikoʻi he 9,8 m/s ² , ʻo kona kuhikuhi i lalo i ke kikowaena o ka Honua. Piʻi ka wikiwiki ma ke ʻano linear i ka manawa ma 9,8 m/s i kēlā me kēia kekona.

I lalo ke kuhikuhi o ka hoʻolalelale ʻana, no laila koho mākou i ke kuhikuhi maikaʻi i lalo.

w – N = ma

N = w – ma

N = 500 – (50)(10)

N = 500 – 500

N = 0

ʻAʻole maopopo

2. E hoʻoholo i ke kaumaha i loko o ke kaula elevator. ʻO ke kaumaha o ka elevator = 2000 kg.

(a) ua hoʻomaha ka elevator

(b) ua hoʻolalelale ʻia ka elevator i lalo ma kahi mau 5 m/s ²

(c) ua hoʻolalelale ʻia ka elevator i luna ma kahi mau 5 m/s ²

(d) ka elevator i ka hāʻule manuahi

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

pāʻoihana

ʻIke ʻia:

Ka nuipa o ka eleweka (m) = 2000 kg

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

kaumaha (w) = mg = (2000)(10) = 20,000 Newtons

Makemake ʻia: Ka ikaika hoʻoluhi (T)

Lōlā:

(a) ua hoʻomaha ka elevator

Ua kū ka elevator no laila ʻaʻohe wikiwiki (a = 0)

Koho mākou i ke kuhikuhi i luna ma ke ʻano he kuhikuhi maikaʻi a me ke kuhikuhi i lalo ma ke ʻano he kuhikuhi maikaʻi ʻole.

Σ F = ma

T – w = 0

T = w

T = 20,000 Newton

ʻO ke kaumaha ma ke kaula (T) = ke kaumaha o ka elevator (w) = 20,000 Newtons

(b) ua hoʻolalelale ʻia ka elevator i lalo ma kahi mau 5 m/s ²

I lalo ke kuhikuhi o ka hoʻolalelale ʻana, no laila koho mākou i ke kuhikuhi maikaʻi i lalo.

w – T = ma

T = w – ma

T = 20,000 – (2000)(5)

T = 20,000 – 10,000

T = 10,000 Newton

c) ua hoʻolalelale ʻia ka elevator i luna ma kahi mau 5 m/s ²

I lalo ke kuhikuhi o ka hoʻolalelale ʻana, no laila koho mākou i ke kuhikuhi maikaʻi i luna.

T – w = ma

T = w + ma

T = 20,000 + (2000)(5)

T = 20,000 + 10,000

T = 30,000 Newton

(d) ka elevator i ka hāʻule manuahi

I lalo ke kuhikuhi o ka hoʻolalelale ʻana, no laila koho mākou i ke kuhikuhi maikaʻi i lalo.

w – T = ma

T = w – ma

T = 20,000 – (2000)(10)

T = 20,000 – 20,000

T = 0

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1. Ka nuipa a me ke kaumaha
2. Ka ikaika maʻamau
3. Ke kānāwai ʻelua o ka neʻe ʻana o Newton
4. ʻO ka ikaika pili
5. Ka neʻe ʻana ma luna o ka ʻili ākea me ka ʻole o ka ikaika friction
6. ʻO ka neʻe ʻana o nā kino ʻelua me ka wikiwiki like ma luna o ka ʻili pālahalaha ʻinoʻino me ka ikaika friction
7. Neʻe ma luna o ka mokulele i hoʻohaʻahaʻa ʻia me ka ʻole o ka ikaika friction
8. Ka neʻe ʻana ma luna o ka mokulele i hoʻohaʻahaʻa ʻia me ka ikaika friction
9. Neʻe ʻana i loko o kahi elevator
10. Hoʻopili ʻia ka neʻe ʻana o nā kino e nā kaula a me nā pulleys
11. ʻElua mau kino me ka nui like o ka wikiwiki
12. Ke hoʻopuni ʻana i kahi piʻo pālahalaha - nā dinamika o ka neʻe pōʻai
13. Ke hoʻopuni ʻana i kahi piʻo panakō - nā dinamika o ka neʻe pōʻai
14. Neʻe like ʻana ma kahi pōʻai ʻākea
15. Ka ikaika centripetal i ka neʻe pōʻai like

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