4 mau laʻana o nā nīnau e pili ana i ka hoʻopili ʻana o nā kānāwai o Newton i ka neʻe pololei o kahi hāpai a i ʻole ka elevator
1. Aia kekahi kanaka me ke kaumaha o 50 kg i loko o kahi eleweka. ʻO ka wikiwiki ma muli o ke koʻikoʻi = 10 m/s2E hoʻoholo i ka nui o ka ikaika maʻamau i hoʻokau ʻia e ka papahele elevator ma luna o ke kanaka inā:
(a) ʻeleweka leo ʻole
(b) neʻe ka elevator i lalo i ka wikiwiki mau
(c) neʻe ka elevator i luna me ka wikiwiki o 5 m/s2
(d) neʻe ka elevator i lalo me ka wikiwiki o 5 m/s2
(e) ʻeleweka hāʻule manuahi
Pahana
Ua ʻike ʻia :
Ka nuipa o ke kanaka (m) = 50 kg
Ka wikiwiki ma muli o ke koʻikoʻi (g) = 10 m/s2
Kaumaha o ke kanaka (w) = mg = (50)(10) = 500 Newtons
Pane :
(a) ʻeleweka leo ʻole
Ua hoʻomaha ka elevator, ʻaʻohe hoʻolalelale (a = 0)
He maikaʻi ka ikaika i kuhikuhi ʻia i luna, he maikaʻi ʻole ia, he ikaika i kuhikuhi ʻia i lalo.
(b) neʻe ka elevator i lalo i ka wikiwiki mau
Neʻe ka elevator i ka wikiwiki mau, ʻaʻohe hoʻolalelale (a = 0)
He maikaʻi ka ikaika i kuhikuhi ʻia i luna, he maikaʻi ʻole ia, he ikaika i kuhikuhi ʻia i lalo.
(c) neʻe ka elevator i luna me ka wikiwiki o 5 m/s2
Neʻe ka elevator i luna me ka wikiwiki (a) o 5 m/s2
He maikaʻi ka ikaika ma ke kuhikuhi like me ka neʻe ʻana o ka mea hāpai, he maikaʻi ʻole ka ikaika ma ke kuhikuhi ʻē aʻe i ka neʻe ʻana o ka mea hāpai.
N – w = ma
N = w + ma
N = 500 + (50)(5)
N = 500 + 250
N = 750 Newton
Ua like ka nui o ka ikaika maʻamau (N) me ke kaumaha (w), no laila ke neʻe ka elevator i luna, ua kaumaha ke kino o ke kanaka. I nā huaʻōlelo ʻē aʻe, ke neʻe ka elevator i luna, ua nui aʻe ke kaumaha o ke kanaka. Inā kū ke kanaka ma luna o kahi unahi, ke neʻe ka elevator i luna, e hōʻike ana ka unahi ua nui aʻe ke kaumaha o ke kanaka.
(d) neʻe ka elevator i lalo me ka wikiwiki o 5 m/s2
Neʻe ka elevator i lalo me ka wikiwiki (a) o 5 m/s2
He maikaʻi ka ikaika ma ke kuhikuhi like me ka neʻe ʻana o ka mea hāpai, he maikaʻi ʻole ka ikaika ma ke kuhikuhi ʻē aʻe i ka neʻe ʻana o ka mea hāpai.
w – N = ma
N = w – ma
N = 500 – (50)(5)
N = 500 – 250
N = 250 Newton
I ka neʻe ʻana o ka elevator i lalo, ua māmā ke kino o ke kanaka. ʻO ia hoʻi, i ka neʻe ʻana o ka elevator i lalo, ua piʻi aʻe ke kaumaha o ke kanaka. Inā e kū ana ke kanaka ma luna o kahi unahi, i ka neʻe ʻana o ka elevator i lalo, e hōʻike ana ke unahi i kahi kaumaha haʻahaʻa.
(e) ʻeleweka hāʻule manuahi
ʻO ke ʻano o ka elevator hāʻule manuahi, ʻo ia hoʻi ka neʻe ʻana o ka elevator i lalo, kahi e hoʻolalelale ai ka elevator (a) = ka hoʻolalelale ʻana o ka umekaumaha (g). No ka laʻana, g = 10 m/s2 a laila a = 10 m/s2
He maikaʻi ka ikaika ma ke kuhikuhi like me ka neʻe ʻana o ka mea hāpai, he maikaʻi ʻole ka ikaika ma ke kuhikuhi ʻē aʻe i ka neʻe ʻana o ka mea hāpai.
w – N = ma
N = w – ma
N = 500 – (50)(10)
N = 500 – 500
N = 0
Ke hāʻule manuahi ka elevator, ʻo ke kaumaha o ke kanaka he ʻole. I nā huaʻōlelo ʻē aʻe, e manaʻo ke kanaka iā lākou iho he kaumaha ʻole. Inā e kū ana ke kanaka ma luna o kahi unahi, i ka neʻe ʻana o ka elevator i lalo, e hōʻike ana ke unahi he ʻole ko lākou nuipa. Ua like kēia kūlana me ka noho ʻana i loko o kahi ākea me ka ʻole o ka umekaumaha.
2. E hoʻoholo i ka nui o ka ikaika umekaumaha ma ke kaula kākoʻo hāpai me ka nuipa o 2000 kg, inā:
(a) ʻeleweka leo ʻole
(b) neʻe ka elevator i lalo me ka wikiwiki o 5 m/s2
(c) neʻe ka elevator i luna me ka wikiwiki o 5 m/s2
(d) ʻeleweka hāʻule manuahi
Manaʻo ʻia ka wikiwiki ma muli o ke koʻikoʻi (g) = 10 m/s2
Pahana
Ua ʻike ʻia :
Ka nui o ka hāpai ʻana (m) = 2000 kg
Ka wikiwiki ma muli o ke koʻikoʻi (g) = 10 m/s2
Kaumaha hāpai (w) = mg = (2000)(10) = 20.000 Newtons
Pane :
(a) ʻeleweka leo ʻole
Ua hoʻomaha ka elevator, ʻaʻohe hoʻolalelale (a = 0)
He maikaʻi ka ikaika i kuhikuhi ʻia i luna, he maikaʻi ʻole ia, he ikaika i kuhikuhi ʻia i lalo.
Ke kū mālie ka hāpai ʻana, ʻo ka ikaika ume ma ke kaula (T) = ke kaumaha o ka hāpai ʻana (w) = 20.000 Newtons
(b) neʻe ka elevator i lalo me ka wikiwiki o 5 m/s2
Neʻe ka elevator i lalo me ka wikiwiki (a) o 5 m/s2
He maikaʻi ka ikaika ma ke kuhikuhi like me ka neʻe ʻana o ka mea hāpai, he maikaʻi ʻole ka ikaika ma ke kuhikuhi ʻē aʻe i ka neʻe ʻana o ka mea hāpai.
w – T = ma
T = w – ma
T = 20.000 – (2000)(5)
T = 20.000 – 10.000
T = 10.000 Newton
Ke neʻe ka elevator i lalo, e liʻiliʻi ka ikaika ume ma ke kaula (T) ma mua o ka wā e kū mālie ai ka elevator.
(c) neʻe ka elevator i luna me ka wikiwiki o 5 m/s2
Neʻe ka elevator i luna me ka wikiwiki (a) o 5 m/s2
He maikaʻi ka ikaika ma ke kuhikuhi like me ka neʻe ʻana o ka mea hāpai, he maikaʻi ʻole ka ikaika ma ke kuhikuhi ʻē aʻe i ka neʻe ʻana o ka mea hāpai.
T – w = ma
T = w + ma
T = 20.000 + (2000)(5)
T = 20.000 + 10.000
T = 30.000 Newton
Ke neʻe ka elevator i luna, e ʻoi aku ka ikaika o ke kaula (T) ma mua o ka wā e kū ai ka elevator.
(d) ʻeleweka hāʻule manuahi
ʻO ke ʻano o ka elevator hāʻule manuahi, ʻo ia hoʻi ka neʻe ʻana o ka elevator i lalo, kahi e hoʻolalelale ai ka elevator (a) = ka hoʻolalelale ʻana o ka umekaumaha (g). No ka laʻana, g = 10 m/s2 a laila a = 10 m/s2
He maikaʻi ka ikaika ma ke kuhikuhi like me ka neʻe ʻana o ka mea hāpai, he maikaʻi ʻole ka ikaika ma ke kuhikuhi ʻē aʻe i ka neʻe ʻana o ka mea hāpai.
w – T = ma
T = w – ma
T = 20.000 – (2000)(10)
T = 20.000 – 20.000
T = 0
Ke hāʻule manuahi kahi elevator, lilo ke kaomi i loko o ke kaula (T) i ʻole. No ka mea ua like ke kaomi i loko o ke kaula me ke kaumaha o ka elevator, ke ʻole ke kaomi i loko o ke kaula, ʻike ʻia hoʻi ke kaumaha o ka elevator he ʻole. Ua like kēia kūlana me ka wā e noho ai kahi mea i loko o kahi hakahaka umekaumaha a i ʻole kahi ākea kahi ʻaʻohe ikaika umekaumaha.
[ʻŌlelo Pelekania: Ka hoʻopili ʻana o ke kānāwai o Newton no ka neʻe ʻana i loko o kahi elevator ]
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 ʻĀkau
D. 420 N
E. 600 ʻĀkau
Pahana
Ua ʻike ʻia:
Nuipaʻa (m) = 60 kg
Ka wikiwiki o ke kanaka a me ka elevator (a) = 3 m/s2
Ka wikiwiki ma muli o ke koʻikoʻi (g) = 10 m/s2
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/s2
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/s2
ʻO ka wikiwiki o ka elevator he 3 m/s2ʻO ke ʻano o ka hōʻailona maikaʻi ʻole, ke neʻe nei ka elevator i luna.
ʻO ka pane pololei ʻo E.
Puna nīnau:
Nā Nīnau Hoʻokolohua Lahui no ke Kino no ke Kula Kiʻekiʻe/Kula Kiʻekiʻe ʻOihana
