Nā nīnau hoʻohālike no ke kānāwai o Newton

20 mau laʻana o nā kānāwai o Newton

Ke Kānāwai Mua o Newton

1. Inā like ka ikaika hopena e hana ana ma kahi mea me ka ʻole, a laila...

(1) ʻaʻole e wikiwiki ka mea

(2) ua hoʻomaha mau nā mea

(3) ʻole ka loli o ka wikiwiki o ka mea

(4) ʻaʻole hiki i kahi mea ke neʻe i kahi laina pololei ma ka wikiwiki mau

ʻO ka ʻoiaʻiʻo…

A. (1), (2) a me (3)

B. (1) a me (3) wale nō

C. (2) a me (4) wale nō

D. (4) wale nō

E. (1), (2), (3) a me (4)

Pahana

ʻO ka pane pololei:

(1) ʻAʻole e wikiwiki ka mea

ʻO ka ikaika hopena e hoʻolalelale ai i kahi mea. Inā ʻaʻohe ka ikaika hopena, ʻaʻole e hoʻolalelale ka mea.

(2) Hoʻomaha mau nā mea

ʻŌlelo ke Kānāwai Mua o Newton inā like ka ikaika hopena e hana ana ma luna o kahi mea me ka ʻole, a laila e noho mālie ka mea e hoʻomaha ana a ʻo ka mea e neʻe ana ma ka wikiwiki mau (neʻe laina like) e neʻe mau ana i ka wikiwiki mau.

(3) ʻO ka loli o ka wikiwiki o ka mea he ʻole

Ka loli o ka wikiwiki = ka wikiwiki. ʻO ka loli o ka wikiwiki o kahi mea he ʻole, ʻo ia hoʻi ka wikiwiki o ka mea he ʻole. Inā ʻo ka wikiwiki he ʻole, a laila ʻo ka hopena o ka ikaika e hana ana ma luna o ka mea he ʻole.

ʻO A ka pane pololei.

Nā Mea i loko o ka Elevator

2. Ke noho ʻo Sandi i loko o kahi elevator paʻa, ʻo kona kaumaha he 500 N. ʻO ka wikiwiki ma muli o ke koʻikoʻi = 10 ms ^–2 . Ke wikiwiki ka elevator, lilo ke kaumaha i loko o ke kaula i 750 N. No laila, ʻo ka wikiwiki o ka elevator…

A. 5,0 ms ^–2

B. 7,5 ms ^–2

C. 10,0 ms ^–2

D. 12,5 ms ^–2

E. 15,0 ms ^–2

Pahana

Ua ʻike ʻia:

Kaumaha code (w) = 500 Newton = 500 kg ms ^–2 (eleweka i ka wā hoʻomaha)

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

ʻŌlelo huna Mass (m) = 500 / 10 = 50 kg

Ka ʻumekaumaha o ke kaula (T) = 750 N (hoʻolalelale ʻia ka elevator)

Ua hoʻowahāwahā ʻia ke kaumaha o ka hāpai.

Nīnau ʻia: Ka wikiwiki o ka elevator

Pane:

Ua kū ka elevator, ʻaʻohe wikiwiki (a = 0). He maikaʻi ka ikaika i luna, he maikaʻi ʻole ka ikaika i lalo.

ΣF = ma

T – w = 0

T = w

T = 500 Newton

Inā e wikiwiki ka hāpai ʻana i lalo, e emi ka ikaika o ke kaula ma mua o 500 Newtons. Ma kekahi ʻaoʻao, inā e wikiwiki ʻia ka hāpai ʻana i luna, e ʻoi aku ka ikaika o ke kaula ma mua o 500 Newtons.

Lilo ke kaumaha o ke kaula i 750 N, e hoʻolalelale ana i ka elevator i luna. He maikaʻi nā ikaika ma ke kuhikuhi like me ka neʻe ʻana o ka elevator, a he maikaʻi ʻole nā ​​​​ikaika ma ke kuhikuhi ʻē aʻe.

T – w = ma

750 – 500 = 50 a

250 = 50 a

a = 250 / 50

a = 5,0 ms ^–2

ʻO A ka pane pololei.

3. Aia kekahi kanaka me ke kaumaha o 60 kg i loko o kahi elevator e neʻe ana i lalo me ka wikiwiki o 3 ms ^-2 . Inā ʻo ka wikiwiki ma muli o ke koʻikoʻi he 10 ms ^-2 , a laila ʻo ka nui o ka ikaika maʻamau i hoʻokau ʻia e ka papahele elevator ma luna o ke kanaka...

A. 180 N

B. 200 N

C. 340 N

D. 420 N

E. 600 N

Pahana

Ua ʻike ʻia:

Nuipaʻa (m) = 60 kg

Ka wikiwiki o ke kanaka a me ka elevator (a) = 3 m/s ²

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

ʻO ke kaumaha (w) = mg = (60)(10) = 600 Newtons

Nīnau ʻia: ka ikaika maʻamau (N)

Pane:

Aia ʻelua mau mana e hana ana ma luna o ke kanaka i loko o kahi elevator, ʻo ia hoʻi ke koʻikoʻi (w) a me ka ikaika maʻamau i hoʻokau ʻia e ka papahele elevator ma luna o ke kanaka (N). Aia ʻekolu mau nui vector, ʻo ia hoʻi ke koʻikoʻi, ka ikaika maʻamau, a me ka wikiwiki o ka elevator, kahi e kuhikuhi ʻia ai ke koʻikoʻi i lalo, e kuhikuhi ʻia ai ka ikaika maʻamau i luna, a e kuhikuhi ʻia ai ka wikiwiki o ka elevator i lalo. Ua koho ʻia ka nui vector i kuhikuhi ʻia i lalo e loaʻa kahi hōʻailona maikaʻi a ua koho ʻia ka nui vector i kuhikuhi ʻia i luna e loaʻa kahi hōʻailona maikaʻi ʻole.

∑ F = ma

w – N = (60)(3)

600 – N = 180

N = 600 – 180

N = 420 Newton

ʻO D ka pane pololei.

4. ʻO Reza, me ke kaumaha o 40 kg, aia i loko o kahi eleweka e neʻe ana i luna. Inā ʻo ka ikaika o ka papahele eleweka ma nā wāwae o Reza he 520 N a ʻo ka wikiwiki ma muli o ke koʻikoʻi he 10 ms ^-2 , a laila ʻo ka wikiwiki o ka eleweka...

A. 1,0 ms ^-2

B. 1,5 ms ^-2

C. 2,0 ms ^-2

D. 2,5 ms ^-2

E. 3,0 ms ^-2

Pahana

Ua ʻike ʻia:

Nuipaʻa (m) = 40 kg

Ka ikaika maʻamau (N) = 520 N

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

Ka ikaika o ke kaumaha (w) = mg = (40)(10) = 400 N

Nīnau ʻia: Ka wikiwiki o ka elevator

Pane:

∑ F = ma

400 – 520 = (40)(a)

-120 = (40)(a)

a = -120/40

a = -3 m/s ²

ʻO ka wikiwiki o ka elevator he 3 m/s² ^. ʻO ka hōʻailona maikaʻi ʻole ke ʻano o ka neʻe ʻana o ka elevator i luna.

ʻO ka pane pololei ʻo E.

5. Aia kekahi kanaka me ke kaumaha o 60 kg i loko o kahi hāpai e neʻe ana i lalo me ka wikiwiki o 3 ms ^-2 . Pehea ka nui o ke kaomi a nā wāwae o kānaka e kau ai ma ka papahele o ka hāpai?

Pahana

Ua ʻike ʻia:

Ka nuipa o ke kanaka (m) = 60 kg

Kaumaha o ke kanaka (w) = mg = (60 kg)(10 m/s ² ) = 600 kg m/s ² = 600 Newtons

Ka wikiwiki o ka elevator (a) = 3 m/s ² , i lalo.

Nīnau ʻia: Pehea ka nui o ke kaomi a nā wāwae o ke kanaka e kau ai ma luna o ka papahele o ka elevator?

Pane:

Neʻe ka elevator i lalo me ka wikiwiki (a) o 3 m/s ^2. He maikaʻi ka ikaika ma ke kuhikuhi like me ka neʻe ʻana o ka elevator, he maikaʻi ʻole ka ikaika ma ke kuhikuhi ʻē aʻe i ka neʻe ʻana o ka elevator.

w – N = ma

N = w – ma

N = 600 – (60)(3)

N = 600 – 180

N = 420 Newton

ʻO kēia ka ikaika maʻamau a ka papahele elevator e hoʻokau ai ma luna o ke kanaka. Kū ke kanaka ma luna o ka elevator i like ai ka nui o ka ikaika maʻamau me ke kaumaha o ke kanaka. Ua like ke kaumaha o ke kanaka me ke kaomi o nā wāwae o ke kanaka ma ka papahele.

ʻŌnaehana Ukana Kaula Pulley

6. ʻElua mau mea A a me B, me ke kaumaha o 6 kg a me 2 kg kēlā me kēia, ua nakinaki ʻia me ke kaula ma luna o kahi pulley e like me ka mea i hōʻike ʻia ma ke kiʻi. Inā hoʻowahāwahā ʻia ka friction ma waena o ke kaula a me ka pulley a ʻo g = 10 ms ^-2 , a laila ʻo ke kaomi ma ke kaula...

A. 20 N

B. 24 N

C. 27 N

D. 30 N

E. 50 N

Pahana

Ua ʻike ʻia:

m _A = 6 kg, m _B = 2 kg, g = 10 m/s ²

w _A = m _A g = (6 kg)(10 m/s ² ) = 60 kg m/s ²

w _B = m _B g = (2 kg)(10 m/s ² ) = 20 kg m/s ²

Nīnau: He aha ka ikaika ume o ke kaula (T)?

Pane:

w _A > w _B no laila neʻe ka ʻōnaehana i ka ʻaoʻao hema (neʻe ʻo m _A i lalo, neʻe ʻo m _B i luna).

Hoʻolalelale

ΣF = ma

w _A – w _B = (m _A + m _B ) a

60 – 20 = (6 + 2) a

40 = (8) a

a = 40 / 8 = 5 m/s ²

ʻO ke kaulahao 

Neʻe ʻo m _A i lalo

w _A – T _A = m _A a

60 – TA ₌ (6)(5)

60 – TA ₌ 30

TA = 60 – ₃₀

T ₂ = 30 Newton

neʻe ʻo m _B i luna

T _B – w _B = m _B a

T _B – 20 = (2)(5)

T _B – 20 = 10

T _B = 10 + 20

T ₁ = 30 Newton

Ka ʻumekaumaha kaula (T) = 30 Newtons.

ʻO D ka pane pololei.

7. E nānā i ke kiʻi ma ka ʻaoʻao! Ua hoʻowahāwahā ʻia ka friction o ke kaula a me ka pulley. Inā ʻo ke kaumaha A = 5 kg, g = 10 m s ^—2 a neʻe ʻo A i lalo me ka wikiwiki o 2,5 m s ^—2 , a laila he aha ke kaumaha o B?

A. 0,5 kg

B. 1 kg

C. 1,5 kg

D. 2 kg

E. 3 kg

Pahana

Ua ʻike ʻia:

Nuipaʻa A (m _A ) = 5 kg

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

Hoʻolalelale A a i ʻole ka hoʻolalelale ʻōnaehana (a) = 2,5 m/s ²

Kaumaha A (w _A ) = (m _A )(g) = (5)(10) = 50 Newtons

Nīnau ʻia: he aha ke kaumaha o B (m _B )?

Pane:

Neʻe ka poloka A i lalo no laila ʻoi aku ke kaumaha o A (w _{A ) ma mua o ke kaumaha o B (w B} ).

E hoʻopili i ke kānāwai ʻelua o Newton:

ΣF = ma

w _A – w _B = (m _A + m _B ) a

50 – (m _B )(10) = (5 + m _B ) (2,5)

50 – 10 m _B = 12,5 + 2,5 m _B

50 – 12,5 = 2,5 m _B + 10 m _B

37,5 = 12,5 m _B

m _B = 3 kg

ʻO ka pane pololei ʻo E.

8. Ua nakinaki ʻia nā mea ʻelua me nā kaumaha o 2 kg a me 3 kg me ke kaula a laila hoʻopaʻa ʻia i kahi pulley nona ke kaumaha i hoʻowahāwahā ʻia e like me ka mea i hōʻike ʻia ma ke kiʻi.

Inā ʻo ka nui o ka hoʻolalelale ʻana o ka umekaumaha = 10 ms ^-2 , ʻo ka ikaika umekaumaha o ke kaula i ʻike ʻia e ka ʻōnaehana he...

A. 20 N

B. 24 N

C. 27 N

D. 30 N

E. 50 N

Pahana

Ua ʻike ʻia:

m1 = ₂ kg, m2 ₌ 3 kg, g = 10 m/ ^s2

w ₁ = (m ₁ )(g) = (2 kg)(10 m/s ² ) = 20 kg m/s ² a i ʻole 20 Newtons

w ₂ = (m ₂ )(g) = (3 kg)(10 m/s ² ) = 30 kg m/s ² a i ʻole 30 Newtons

Nīnau: He aha ka ikaika ume o ke kaula (T)?

Pane:

w ₂ > w ₁ no laila neʻe ka ʻōnaehana i ka ʻaoʻao ʻākau (neʻe ʻo m ₂ i lalo, neʻe ʻo m ₁ i luna).

Hoʻolalelale

ΣF = ma

w ₂ – w ₁ = (m ₁ + m ₂ ) a

30 – 20 = (2 + 3) a

10 = (5) a

a = 10 / 5 = 2 m/ ^s2.

ʻO ke kaulahao 

neʻe iho ʻo m ₂

w ₂ – T ₂ = m ₂ a

30 – T ₂ = (3)(2)

30 – T ₂ = 6

T ₂ = 30 – 6

T ₂ = 24 Newton

neʻe ʻo m ₁ i luna

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 ʻumekaumaha kaula (T) = 24 Newtons.

ʻO ka pane pololei ʻo B.

9. Ua hoʻopili ʻia ʻelua mau poloka e kahi pulley laumania a ua hoʻowahāwahā ʻia ke kaumaha o ka pulley e like me ka mea i hōʻike ʻia ma ke kiʻi. Mass A = m _A , mass B = m _B a hāʻule ka poloka B me ka wikiwiki a. Inā ʻo ka wikiwiki ma muli o ke koʻikoʻi he g, a laila ʻo ka nui o ke kaulahao e kū nei ma ka poloka B…

A. T = m_B.a

B. T = m _A (a – g)

C. T = mA ₍ g – a)

D. T = mB ₍ a – g)

E. T = mB ₍ g – a)

Pahana

He laumania ka ʻili pālahalaha no laila ʻaʻohe ikaika frictional e kāohi ana i ka neʻe ʻana o ka poloka A. ʻO ka ikaika e hoʻoneʻe ai i ka ʻōnaehana poloka ʻo ia ke kaumaha o ka poloka B.

E helu i ka wikiwiki o ka ʻōnaehana:

E helu i ka ikaika o ke kaula (T):

E noʻonoʻo i ka neʻe ʻana o kekahi o nā mea, no ka laʻana ʻo A. Neʻe ʻo A i ka ʻākau.

E pani iā ​​m _A ma ka hoohalike 1 me m _A ma ka hoohalike 2.

ʻO ka pane pololei ʻo E.

10. Ua kau ʻia kahi poloka me ke kaumaha o 10 kg ma luna o kahi papahele ʻinoʻino a laila huki ʻia e ka ikaika ākea F. Inā ʻo μ ke koina o ka friction static_s = 0,5 a me ke koina o ka friction kinetic μ_k = 0,3. E hoʻoholo i ka nui o ka ikaika friction ke kokoke ka poloka e neʻe. (g = 10 m/s²)
Pahana
E neʻe pololei ka poloka inā ʻo ka nui o ka ikaika huki = ka nui o ka ikaika friction static kiʻekiʻe loa. Hana ka friction static ma luna o kahi mea (kāohi i ka neʻe ʻana o ka mea) ke huki ʻia ka mea akā ʻaʻole i neʻe ka mea. Loaʻa i ka friction static ka waiwai kiʻekiʻe loa ke kokoke ka neʻe ʻana o ka mea (ʻaʻole i neʻe ka mea, kokoke ka neʻe ʻana o ka mea). I ka ʻaoʻao ʻē aʻe, hana ka friction kinetic ma luna o kahi mea (kāohi i ka neʻe ʻana o ka mea) ke neʻe mua ka mea.
Ua ʻike ʻia:
Nīnau: Ka ikaika haʻalulu paʻa kiʻekiʻe loa (f_s)?
Pane:
Inā aia ka mea ma luna o kahi mokulele pālahalaha e like me ke kiʻi, ʻo ka nui o ka ikaika maʻamau = ke kaumaha o ka mea.
Ka ikaika maʻamau (N) = ka umekaumaha (w) = 100 Newtons
Ka haʻilula ikaika haʻalulu paʻa kiʻekiʻe loa:
ʻAʻole hoʻohana ʻia ke koina o ka friction kinetic i nā helu ʻana.

11. Ua hoʻopili ʻia ʻelua mau poloka e ke kaula māmā i huki ʻia e ka ikaika ākea F = 20 N (e nānā i ke kiʻi). Inā g = 10 ms^-2 a ʻo ke koina o ka friction kinetic ma waena o ka poloka a me ka ʻili he 0,1, e hoʻoholo i ka nui o ka wikiwiki o ka poloka...
Pahana
Ua ʻike ʻia:
Nīnau ʻia: ka wikiwiki (a) o ka poloka?
Pane:
12. Ua hoʻonohonoho ʻia ka poloka A me ke kaumaha o 2 kg a me B me ke kaumaha o 4 kg e like me ka mea i hōʻike ʻia ma ke kiʻi. Inā ʻo ke koina o ka friction o ka papahele he 3 manawa o ke koina o ka friction o ka poloka B, e neʻe ka poloka A me ka wikiwiki o 5 m/s.^-2No laila, ʻo ka lakio o ka ikaika friction ma waena o ka poloka A a me ka papahele i nā poloka A a me B he… g = 10 m/s²
Pahana
Ua ʻike ʻia:
Ua nīnau ʻia:
Hoʻohālikelike ʻia o ka ikaika frictional o ka poloka A a me ka papahele (f_{s A}) me ka ikaika friction o nā poloka A a me B (f_{s B})?
Pane:

13. E nānā i ke kiʻi ma ka ʻaoʻao! ʻO ke kaumaha o kēlā me kēia poloka he m.₁ = 2 kg a me m₂ = 3 kg a ua hoʻowahāwahā ʻia ke kaumaha o ka pulley. Inā laumania ka ʻili o ka mokulele a ʻo g = 10 ms^-2, a laila ʻo ka wikiwiki o ka ʻōnaehana he ….
A. 0,5 ms^-2
B. 2,0 ms^-2
C. 2,5 ms^-2
D. 4,0 ms^-2
E. 6,0 ms^-2
Pahana
Ua ʻike ʻia:
m₁ = 2 kg, m₂ = 3 kg, g = 10 ms^-2
w₂ = m₂ g = (3)(10) = 30 kg m/s² a i ʻole 30 Newtons
Nīnau: Ka wikiwiki o ka ʻōnaehana (a)?
Pane:
14. Ua hoʻopili ʻia kahi mea me ke kaumaha e ke kaula e hele ana ma o kahi pulley laumania e like me ka mea i hōʻike ʻia ma ke kiʻi. Inā m₁ = 2 kg, m₂ = 3 kg a me g = 10 ms^-2, a laila ʻo ka nui o ka ikaika ume o ke kaula T he…
A. 10,2 N
B. 13,3 N
C. 15,5 N
D. 18,3 N
E. 24,0 N
Pahana
Ua ʻike ʻia:
m₁ = 2 kg, m₂ = 3 kg, g = 10 ms^-2
w₁ = (2)(10) = 20 Newton
w₂ = (3)(10) = 30 Newton
Nīnau: He aha ka nui o ka ikaika ume ma ke kaula (T)?
Pane:
w₂ = 30 ʻOi aku ka nui o nā Newton ma mua o w₁ = 20 Newtons no laila m₂ neʻe i lalo, m₁ neʻe i luna.
ʻO ke ʻano hana o ke kānāwai ʻelua o Newton:
Ka ikaika o ke kaula?
Wahi a ke kuhikuhi o ka neʻe ʻana o ka ʻōnaehana a i ʻole ke kuhikuhi o ka wikiwiki o ka ʻōnaehana, ke kuhikuhi o ka ikaika umekaumaha m₂ i lalo, ke kuhikuhi o ka ikaika uʻi kaula ma luna o m₂ i luna:
w₂ - T₂ = m₂ a
30 – T₂ = (3)(2)
30 – T₂ = 6
T₂ = 30 - 6
T₂ = 24 Newton
Ke kuhikuhi o ke koʻikoʻi m₁ i lalo, ke kuhikuhi o ka ikaika uʻi kaula ma luna o m₁ i luna:
T₁ - w₁ = (m₁) ('ai)
T₁ – 20 = (2)(2)
T₁ - 20 = 4
T₁ = 4 + 20
T₁ = 24 Newton
Ka ikaika o ke kaula (T) = T₁ =T₂ = 24 Newton.

15. ʻElua mau poloka, me ke kaumaha o 4 kg kēlā me kēia, ua hoʻopili ʻia e ke kaula a me ka pulley e like me ka mea i hōʻike ʻia ma ke kiʻi. He laumania ka ʻili a me ka pulley. Inā huki ʻia ka poloka B me ka ikaika ākea o 50 N, ʻo ka wikiwiki o ka poloka… (g = 10 m/s²)
A. 1,25 m/s²
B. 7,5 m/s²
C. 10 m/s²
D. 12,5 m/s²
E. 15 m/s²
Pahana
Ua ʻike ʻia:
m_A = 4 kg, m_B = 4 kg, g = 10 m/s²
w_A = (m_A)(g) = 4)(10) = 40 Newton
F = 50 Newton
Nīnau ʻia: ka hoʻolalelale ʻana o ka ʻōnaehana?
Pane:
ʻO ke ʻano hana o ke kānāwai ʻelua o Newton:
ʻO ka wikiwiki o nā poloka ʻelua he 1,25 m/s². Ke kuhikuhi o ka neʻe ʻana o nā poloka ʻelua = ke kuhikuhi o ka ikaika tensile F.

16. E nānā i ke kiʻi ma ka ʻaoʻao! ʻO ke kaumaha o nā poloka he m ₁ = 6 kg a me m ₂ = 4 kg, a ua hoʻowahāwahā ʻia ke kaumaha o ka pulley. Inā laumania ka ʻili o ka mokulele a ʻo g = 10 m s ⁻² , a laila ʻo ka wikiwiki o ka ʻōnaehana….

A. 0,5 ms^-2
B. 2,0 ms^-2
C. 2,5 ms^-2
D. 4,0 ms^-2
E. 5,0 ms^-2

Pahana
Ua ʻike ʻia:
m₁ = 6 kg, m₂ = 4 kg, g = 10 m/s²
w₁ = m₁ g = (6 kg)(10 m/s)²) = 60 kg m/s² a i ʻole 60 Newtons
w₂ = m₂ g = (4 kg)(10 m/s)²) = 40 kg m/s² a i ʻole 40 Newtons
Nīnau ʻia: ka wikiwiki o ka ʻōnaehana (a)?
Pane:

m₁aia ma luna o kahi ʻili laumania a pālahalaha me ka ʻole o ka friction i hiki ai i ka ʻōnaehana ke hoʻokele ʻia e umekaumaha poloka 2.
Terapkan Ke kānāwai ʻelua o Newton :
∑F = ma
w₂ = (m₁ +m₂) a
40 N = (6 kg + 4 kg) a
40 N = (10 kg) a
a = 40 N / 10 kg
a = 4 m/s²
ʻO D ka pane pololei.

17. ʻElua mau poloka, me ke kaumaha o 2 kg kēlā me kēia, ua hoʻopili ʻia e ke kaula a me ka pulley e like me ka mea i hōʻike ʻia ma ke kiʻi. He laumania ka ʻili a me ka pulley. Inā huki ʻia ka poloka B me ka ikaika ākea o 40 N, ʻo ka wikiwiki o ka poloka… (g = 10 m/s ² )

A. 5 m/s²
B. 7,5 m/s²
C. 10 m/s²
D. 12,5 m/s²
E. 15 m/s²

Kūkākūkā:
Ua ʻike ʻia:
m_A = m_B = 2 kg, g = 10 m/s², F = 40 N
w_A = mg = (2)(10) = 20 N
Nīnau: ka wikiwiki o ka poloka (a)?
Pane:
He laumania ka ʻili o ka poloka, no laila ʻo ka ikaika e hoʻopilikia ai i ka neʻe ʻana o ka poloka he ikaika F a me ke kaumaha o ka poloka A.
E hoʻopili i ke kānāwai ʻelua o Newton:
∑F = ma
F - w_A = (m_A +m_B) a
40 – 20 = (2 + 2) a
20 = (4) a
a = 20 / 4
a = 5 m/s²
ʻO A ka pane pololei.

mokulele hilig

18. Aia kahi poloka me ke kaumaha o 2 kg ma luna o kahi mokulele hilig laumania me ke kihi o ka hilig = 30^o, i neʻe ai ka poloka me ka wikiwiki mau. Inā g = 10 ms^-2, a laila ʻo ka nui o ka ikaika e hoʻoneʻe ai i ka poloka he...
A. 5 N
B. 6 N
C. 7 N
D. 8 N
E. 10 N
Pahana
Ua ʻike ʻia:
m = 2 kg, g = 10 m/s², theta = 30^o
w = mg = (2)(10) = 20 kg m/s² = 20 N
Nīnau: He aha ka ikaika e hoʻoneʻe ai i ka poloka?
Pane:

ʻO ka ikaika e hoʻoneʻe ai i ka poloka he w_x.
w_x = w sin teta
w_x = (20 N)(sin 30^o)
w_x = (20 N)(0,5)
w_x = 10 N.
ʻO ka ikaika e hoʻoneʻe ai i ka poloka he 10 Newtons.
ʻO ka pane pololei ʻo E.

19. Ua hoʻopili ʻia ʻelua mau poloka e ke kaula māmā i huki ʻia e ka ikaika ākea F = 24 N. g = 10 ms^-2 a he pahee ka ʻili o ka papahele. ʻO ka nui o ka wikiwiki o ka poloka me ka hoʻohana ʻana i ke kānāwai ʻelua o Newton no kēlā me kēia mea...
Pahana
Ua ʻike ʻia:
m₁ = 2 kg, m₂ = 4 kg, F = 24 N
Nīnau: He aha ka wikiwiki o ka poloka (a)?
Pane:
ʻO ka nui o ka wikiwiki o ka poloka he 4 m/s².

20. I loko o kahi elevator paʻa, ʻo ke kaumaha o Sandi he 500 N. ʻO ka wikiwiki ma muli o ke koʻikoʻi = 10 ms^-2. Ke hoʻolalelale ka elevator, lilo ke kaomi i loko o ke kaula i 750 N. No laila, ʻo ka hoʻolalelale o ka elevator he...
A. 5,0 ms^-2
B. 7,5 ms^-2
C. 10,0 ms^-2
D. 12,5 ms^-2
E. 15,0 ms^-2
Pahana
Ua ʻike ʻia:
w = 500 N, g = 10 m/s², T = 750 N
Nīnau: ka wikiwiki o ka elevator (a)?
Pane:
Ka nui o ka ʻōlelo huna:
w = mg
500 = mika (10)
m = 500 / 10
m = 50 kg
ʻAʻole ʻike ʻia ke kaumaha o ka hāpai ʻana no laila ʻo ka huina kaumaha o ka hāpai ʻana a me nā mea i loko = ke kaumaha o ke code.
Wahi a ke kānāwai mua o Newton, inā kū ka elevator a laila ʻo ka hopena o ka ikaika = 0.
ʻO ka ikaika ume o ke kaula (T) ke kūpaʻa ka hāpai = 500 N.
Ke hoʻolalelale ka elevator, lilo ka ikaika o ke kaula (T) i 750 N a i ʻole e piʻi aʻe ma 250 N.

ʻO ka wikiwiki o ka elevator he 5 m/s² a ʻo ke kuhikuhi o ka hoʻolalelale = ke kuhikuhi o ka neʻe ʻana o ka elevator i luna.

Puna nīnau:

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