8 mau laʻana o nā nīnau kuʻi
Kuʻi elastic kūpono
1. ʻElua mau mea A (3 kg) a me B (5 kg) e neʻe ana ma ke ala like me nā wikiwiki o 8 ms –1 a me 4 ms –1 . Inā paʻi ka mea A i ka mea B me ka elasticity kūpono, a laila ʻo ka wikiwiki o kēlā me kēia mea ma hope o ke kuʻi ʻana he...
A. 3 ms –1 a me 7 ms –1
B. 6 ms –1 a me 10 ms –1
C. 4,25 ms –1 a me 10 ms –1
D. 5,5 ms –1 a me 5,5 ms –1
E. 8 ms –1 a me 4 ms –1
Pahana
Ua ʻike ʻia:
Ka nuipa o ka mea A (m1 ) = 3 kg
Ka nuipa o ka mea B (m2 ) = 5 kg
ʻO ka wikiwiki o ka mea A (v 1 ) = 8 ms –1
ʻO ka wikiwiki o ka mea B (v 2 ) = 4 ms –1
Kuʻi elastic kūpono
Nīnau ʻia: v 1 ' a me v 2 '
Pane:
Inā he ʻokoʻa nā nuipa o nā mea e kuʻi ana me ke ʻano elastic a ʻaʻole ʻike ʻia ka wikiwiki o nā mea ʻelua ma hope o ke kuʻi ʻana, a laila ua helu ʻia ka wikiwiki ma hope o ke kuʻi ʻana me ka hoʻohana ʻana i kēia kaulike:
Inā e neʻe ana nā mea ʻelua ma ke kuhikuhi like, he maikaʻi ko lākou wikiwiki. Inā e neʻe ana nā mea ʻelua ma nā kuhikuhi ʻē aʻe, he maikaʻi ka wikiwiki o kekahi mea a he maikaʻi ʻole ka wikiwiki o kekahi mea.
No laila, ʻo ka wikiwiki o ka mea A (v 1 ') ma hope o ke kuʻi ʻana he 3 m/s a ʻo ka wikiwiki o ka mea B (v 2 ') ma hope o ke kuʻi ʻana he 7 m/s.
ʻO A ka pane pololei.
2. He pōpō nona ka momentum P e kuʻi ana i ka paia a lele. He elastic kūpono ke kuʻi ʻana a he perpendicular ke kuhikuhi. ʻO ka loli o ka momentum o ka pōpō he...
A. ʻole
B. ʻaoʻao/4
C. ʻaoʻao/4
D.P.
E. 2P
Pahana
Ua ʻike ʻia:
Ka nuipa o ka pōpō = m
ʻO ka wikiwiki o ka pōpō ma mua o ka hopena = v
ʻO ka wikiwiki o ka pōpō ma hope o ka hopena = -v (lele ka pōpō i ka hema)
Ka ikaika o ka pōpō ma mua o ke kuʻi ʻana (p o ) = mv
Ka ikaika o ka pōpō ma hope o ke kuʻi ʻana (p t ) = m (-v) = – mv
Nīnau: Pehea ka nui o ka loli o ka momentum o ka pōpō?
Pane:
Hoʻololi i ka momentum:
Δp = pt – p o
Δp = – mv – mv
Δp = – 2 mv
Δp = -2p
ʻO ka nui o ka loli o ka momentum o ka pōpō he 2p. Hōʻike ka hōʻailona maikaʻi ʻole i ke kuhikuhi.
ʻO ka pane pololei ʻo E.
3. ʻElua mau mea A a me B me ke kaumaha like e neʻe ana kekahi i kekahi. Neʻe ʻo A i ka Hikina a ʻo B i ke Komohana, me nā wikiwiki V a me 2V pakahi. Inā ʻike nā mea i kahi kuʻi elastic kūpono, a laila ma hope koke iho o ke kuʻi ʻana...
A. V A = V i ke Komohana, V B = V i ka Hikina
B. V A = 2V i ke Komohana, V B = 2V i ka Hikina
C. V A = 2V i ke Komohana, V B = V i ka Hikina
D. V A = V i ke Komohana, V B = 2V i ka Hikina
E. V A = 2V i ka Hikina, V B = V i ke Komohana
Pahana
Ua ʻike ʻia:
Ua like ka nuipa o nā mea ʻelua.
Neʻe ʻo A i ka hikina me ka wikiwiki o V
Neʻe ʻo B i ke komohana me ka wikiwiki o 2V
Nīnau: Ka wikiwiki o A a me B ma hope o ke kuʻi ʻana
Pane:
Inā like nā kaumaha o nā mea ʻelua a he elastic kūpono ke kuʻi ʻana, a laila hoʻololi ka wikiwiki o nā mea ʻelua ma hope o ke kuʻi ʻana.
No laila ma hope o ke kuʻi ʻana, neʻe ʻo A i ke komohana me ka wikiwiki o 2V a neʻe ʻo B i ka hikina me ka wikiwiki o V.
ʻO C ka pane pololei.
Kuʻi ʻana o ka Elastic hapa
4. ʻElua mau mea me ke kaumaha like e neʻe pololei ana kekahi i kekahi e like me ka mea i hōʻike ʻia ma ke kiʻi!
Inā ʻo v 2 ' ka wikiwiki o ka mea (2) ma hope o ke kuʻi ʻana i ka ʻākau me ka wikiwiki o 5 ms –1 , a laila ʻo ka nui o ka wikiwiki v 1 ' (1) ma hope o ke kuʻi ʻana he…..
A. 7 ms −1
B. 9 ms −1
C. 13 ms −1
D. 15 ms −1
E. 17 ms −1
Pahana
Ua ʻike ʻia:
Ua like ke kaumaha o nā mea ʻelua = m
ʻO ka wikiwiki o ka mea 1 ma mua o ke kuʻi ʻana (v 1 ) = 8 m/s
ʻO ka wikiwiki o ka mea 2 ma mua o ke kuʻi ʻana (v 2 ) = 10 m/s
ʻO ka wikiwiki o ka mea 2 ma hope o ke kuʻi ʻana (v 2 ') = 5 m/s
Nīnau: Ka wikiwiki o ka mea 1 ma hope o ke kuʻi ʻana (v 1 ')
Pane:
He kuʻi elastic kīnā ʻole kēia. Ua helu ʻia ʻo v 1 ' me ka hoʻohana ʻana i ke kānāwai o ka mālama ʻana i ka momentum:
m 1 v 1 + m 2 v 2 = m 1 v 1 ' + m 2 v 2 '
m (v 1 + v 2 ) = m (v 1 ' + v 2 ')
v 1 + v 2 = v 1 ' + v 2 '
8 + 10 = v 1 ' + 5
18 = v 1 ' + 5
v 1 ' = 18-5
v 1 ' = 13 m/s
ʻO C ka pane pololei.
Kuʻi ʻole ʻia
5. He pōkā 10-kalama e holo ana ma ka wikiwiki o 100 m/s -1 e kuʻi ana i kahi poloka lāʻau paʻa a paʻa i loko. Inā he 490 kalama ke kaumaha o ka poloka lāʻau, ʻo ka wikiwiki o ka poloka lāʻau a me ka pōkā ma hope koke iho o ke kuʻi ʻana he...
A. 1,0 ms -1
B. 2,0 ms -1
C. 2,5 ms -1
D. 4,0 ms -1
E. 5,0 ms -1
Pahana
Ua ʻike ʻia:
Ka nuipa o ka pōkā (m1 ) = 10 grams
Ka wikiwiki o ka pōkā (v 1 ) = 100 ms -1
Ka nuipa o ka poloka (m2 ) = 490 grams
Ka wikiwiki o ka poloka (v 2 ) = 0 m/s (poloka i ka wā hoʻomaha)
Nīnau: ʻO ka wikiwiki o ka poloka lāʻau a me ka pōkā ma hope koke iho o ke kuʻi ʻana
Pane:
Paʻi ka pōkā i kahi poloka lāʻau paʻa a paʻa i loko, no laila he kuʻi inelastic kēia. ʻO ke ʻano hana no kahi kuʻi inelastic penei:
Ka ikaika ma mua o ke kuʻi ʻana = ka ikaika ma hope o ke kuʻi ʻana
m 1 v 1 + m 2 v 2 = (m 1 + m 2 ) v'
(10)(100) + (490)(0) = (10 + 490) v'
1000 + 0 = 500 v'
1000 = 500 v'
v' = 1000 / 500
v' = 2 m/s = 2 ms -1
ʻO ka pane pololei ʻo B.
6. Ua pā ʻia kekahi kalaka e neʻe ana ma ka wikiwiki o 10 m/ s e kekahi kaʻa e neʻe ana ma ka wikiwiki o 20 m/ s . Ma hope o ke kuʻi ʻana, ua kuʻi nā kaʻa ʻelua kekahi i kekahi. Inā he 1400 kg ke kaumaha o ke kalaka a he 600 kg ke kaumaha o ke kaʻa, ʻo ka wikiwiki o nā kaʻa ʻelua ma hope o ke kuʻi ʻana he...
A. 6 ms –1
B. 9 ms –1
C. 11 ms –1
D. 13 ms –1
E. 17 ms –1
Pahana
Ma hope o ke kuʻi ʻana, ua paʻa pū nā kaʻa ʻelua, a ʻo ka hopena he kuʻi ʻole i ka elastic.
Ua ʻike ʻia:
Ka wikiwiki o ke kalaka (v 1 ) = 10 m/s
Ka wikiwiki o ke kaʻa (v 2 ) = 20 m/s
Ka nuipaʻa o ke kalaka (m1 ) = 1400 kg
Ke kaumaha o ke kaʻa (m2 ) = 600 kg
Nīnau: ka wikiwiki o nā kaʻa ʻelua ma hope o ke kuʻi ʻana (v)
Pane:
ʻAno hoʻohālikelike kuʻi ʻole:
m 1 v 1 + m 2 v 2 = (m 1 + m 2 ) v
(1400)(10) + (600)(20) = (1400 + 600) v
26000 = 2000 v
v = 13 m/s
ʻO D ka pane pololei.
7. ʻO kahi pōkā 20 gram e neʻe ana ma ka wikiwiki o 10 m/s - 1 e kuʻi pālahalaha ana i kahi poloka 60 gram e kū mau ana ma ka papahele. Inā paʻa ka pōkā i loko o ka poloka, a laila ʻo ka wikiwiki o kēia manawa o ka poloka….
A. 1,0 ms -1
B. 1,5 ms -1
C. 2,0 ms -1
D. 2,5 ms -1
E. 3,0 ms -1
Pahana
Ua ʻike ʻia :
Ka nuipa o ka pōkā (m P ) = 20 grams = 0,02 kg
Ka nuipa poloka (m B ) = 60 grams = 0,06 kg
Ka wikiwiki mua o ka pōkā (v P ) = 10 m/s
Ka wikiwiki mua o ka poloka (v B ) = 0
Nīnau : ka wikiwiki o ka pōkā a me ka poloka ma hope o ke kuʻi ʻana (v')
Pane :
ʻO ke ʻano hana no ke kānāwai o ka mālama ʻana i ka momentum inā pili pū nā mea ʻelua ma hope o ke kuʻi ʻana:
m P v P + m B v B = (m P + m B ) v'
(0,02)(10) + (0,06)(0) = (0,02 + 0,06) v'
0,2 + 0 = 0,08 v'
0,2 = 0,08 v'
v' = 0,2 / 0,08
v' = 2,5 m/s
ʻO D ka pane pololei.
8. ʻElua mau kaʻa A a me B, he 1,5 kg ke kaumaha o kēlā me kēia, e neʻe ana kekahi i kekahi me v A = 4 ms -1 a me v B = 5 ms -1 e like me ka mea i hōʻike ʻia ma ke kiʻi. Inā kuʻi nā kaʻa ʻelua ma ke ʻano inelastic, a laila ʻo ka wikiwiki o nā kaʻa ʻelua ma hope o ke kuʻi ʻana he...
A. 4,5 ms-1 i ka ʻākau
B. 4,5 ms -1 ma ka hema
C. 1,0 ms -1 ma ka hema
D. 0,5 ms -1 ma ka hema
E. 0,5 ms -1 ma ka ʻākau
Pahana
Ua ʻike ʻia:
Ke kaumaha o ke kaʻa A (m A ) = 1,5 kg
ʻO ke kaumaha o ke kaʻa B (m B ) = 1,5 kg
ʻO ka wikiwiki o ke kaʻa A ma mua o ke kuʻi ʻana (v A ) = 4 m/s (maikaʻi ma ka ʻākau)
ʻO ka wikiwiki o ke kaʻa B ma mua o ke kuʻi ʻana (v B ) = -5 m/s (maikaʻi ʻole i ka hema)
Nīnau: Inā he inelastic ke kuʻi ʻana, e hoʻoholo i ka wikiwiki o nā kaʻa ʻelua ma hope o ke kuʻi ʻana.
Pane:
Ke kānāwai o ka mālama ʻana i ka momentum:
m A v A + m B v B = (m A + m B ) v'
(1,5)(4) + (1,5)(-5) = (1,5 + 1,5) v'
6 – 7,5 = (3) v'
-1,5 = (3) v'
v' = -1,5 / 3
v' = -0,5 m/s
ʻO ke ʻano o ka hōʻailona maikaʻi ʻole ma hope o ke kuʻi ʻana, neʻe nā mea ʻelua i ka hema, ma ke kuhikuhi like me ke kaʻa B. He mea kūpono kēia no ka mea ʻoi aku ka nui o ka momentum o ke kaʻa B ma mua o ka momentum o ke kaʻa A.
Puna nīnau:
Nā Nīnau Hoʻokolohua Lahui no ke Kino no ke Kula Kiʻekiʻe/Kula Kiʻekiʻe ʻOihana
