Ngā tauira pātai me ngā tātai mō ngā ture a Newton
Te Ture Tuatahi a Newton
1. Kei roto tētahi tangata i tētahi ararewa e neke haere ana i te tere pumau ki runga. Ko te taumaha o te tangata he 800 N. Kātahi ka motu te taura maitai e kukume ana i te ararewa, ka taka te ararewa. Ko te kaha noa mai i te papa o te ararewa ki runga i te tangata i mua tonu atu, ā, i muri tonu i te motuhanga o te taura maitai, ko….
- 800 N me te 0
- 800 N me 800 N
- 1600 N me te 0
- 1600 N me 800 N
Kōrero
E mōhiotia ana:
Taumaha (w) = 800 Newton
Pātai: Ko te kaha noa (N) e pā ana ki te tangata i mua tonu atu, ā, i muri tonu i te motu o te taura maitai
Whakautu:
I mua tata i te whatinga o te taura maitai
Ina tū te tangata ki runga i te papa o te ararewa, ka pā te kaha o te taumaha ki te tangata, ā, ka heke te ahunga o te kaha (tirohia te whakaahua i raro nei). Kei te tū tonu te tangata i roto i te ararewa, nō reira me whai kaha noa e taurite ana i te taumaha o te tangata, ko te ahunga o tēnei kaha ki runga, ā, he rite te kaha ki te kaha taumaha. Ko te kaha noa e pā ana ki te tangata e te papa, ā, ka pā tēnei kaha ki te tangata.
Nā te mea e tū ana te tangata i roto i te ararewa, ā, e neke ana te ararewa i te tere pumau (kāore he whakaterenga), ko te kaha e pā ana ki te tangata he kore.
∑F = 0
N – w = 0
N = w
N = 800 Niutona
I muri i te whatinga o te taura maitai
I muri i te whati o te taura maitai, ka hinga noa te ararewa me te tangata, ā, ko te rahi me te ahunga o te whakaterenga hinga noa o te ararewa me te tangata he ōrite ki te whakaterenga nā te kaha ā-papa i runga i te whenua. Ka hinga noa te ararewa me te tangata, ā, kāore he kaha noa e pā ana ki te papa o te ararewa ki te tangata. Kei te hinga te tangata, ā, kāore e taea e ngā waewae o te tangata te pēhi i te papa o te ararewa nā te mea kei te hinga hoki te ararewa.
Ko te whakautu tika ko A.
2. E toru ngā kaha, ko ia kaha he F1 = 22 N, F2 = 18 N, me F3 = 40 N, ka pā ki tētahi poraka rakau. Ko ngā kaha e pā ana ki te poraka, e whai ana i te ture tuatahi a Newton, e whakaaturia ana i te ahua...
Kōrero
Te Ture Tuatahi a Newton: Te kaha hua ( ΣF) = 0.
A. F 1 + F 2 – F 3 = 22 N + 18 N – 40 N = 40 N – 40 N = 0
B. F 2 + F 3 – F 1 = 18 N + 40 N – 22 N = 58 N – 22 N = 36 N (ki te taha matau)
C. F 2 + F 3 – F 1 = 18 N + 40 N – 22 N = 58 N – 22 N = 36 N (ki te taha matau)
D. F 1 + F 3 – F 2 = 22 N + 40 N – 18 N = 62 N – 18 N = 44 N (ki te taha mauī)
Ko te whakautu tika ko A.
Te Ture Tuarua a Newton
3.
Tirohia te pikitia!
Ka tōia tētahi poraka 40 kg me te kaha o te 200 N, ka hua ake he whakaterenga o te 3 m/s.2 Nō reira, ko te rahi o te kaha waku e pā ana ki te mea/poraka ko...
- 15 N
- 40 N
- 43 N
- 80 N
Kōrero
E mōhiotia ana:
Taumaha (m) = 40 kg
Te kaha (F) = 200 N
Whakaterenga (a) = 3 m/s2
Pātai: Te rahi o te kaha waku (F)g)
Whakautu:
Te tātai ture tuarua a Newton:
∑F = ma
Whakaahuatanga: ∑F = te kaha hua, m = te papatipu, a = te whakaterenga
Ko te ahunga o te kaha F kei te taha matau, ko te ahunga o te waku kei te taha maui (kei te ritenga kē te ahunga o te waku ki te ahunga o te nekehanga o te mea). Ka whiriwhiria te ahunga ki te taha matau hei pai, ā, ko te ahunga ki te taha maui hei kino.
∑F = ma
Wh – Whg = mā
200 – Fg = (40)(3)
200 – Fg = 120
Fg = 200 - 120
Fg = 80 Niutona
Ko te whakautu tika ko D.
4. Kei runga i te poraka B he 300 karamu te taumaha o te poraka A, kātahi ka panaia te poraka B e te kaha 5 N ki runga poutū. Ki te kore ngā poraka e neke tetahi ki tetahi, ko te rahi o te kaha noa e pā ana ki te poraka B i runga i te poraka A ko….
- 1 N
- 1,25 N
- 2 N
- 3 N
Kōrero
E mōhiotia ana:
Te kaha pana (F) = 5 Newton
Te taumaha o te poraka A (mA) = 100 karamu = 0,1 kg
Te taumaha o te poraka B (mB) = 300 karamu = 0,3 kg
Te whakaterenga nā te kaha ā-papa (g) = 10 m/s2
Taumaha o te poraka A (wA) = (0,1 kg)(10 m/s2) = 1 kg m/s2 = 1 Niutona
Taumaha o te poraka B (wB) = (0,3 kg)(10 m/s2) = 3 kg m/s2 = 3 Niutona
Pātai: Te kaha noa i te poraka B i runga i te poraka A
Whakautu:
He maha ngā kaha e pā ana ki ngā poraka e rua, e whakaaturia ana i te pikitia i raro nei.
F = te kaha pana (e mahi ana ki te poraka B)
wA = te kaha o te taumaha o te poraka A (e pā ana ki te poraka A)
wB = te taumaha o te poraka B (e pā ana ki te poraka B)
NA = te kaha noa o te poraka B i runga i te poraka A (e mahi ana i runga i te poraka A)
NA' = te kaha noa o te poraka A i runga i te poraka B (e mahi ana i runga i te poraka B)
Whakaarohia ngā poraka e rua hei pūnaha kotahi:
Whakamahia te ture tuarua a Newton ki ngā poraka e rua:
∑F = ma
F – wA - wB +NA - NA' = (mA +mB) a
NA me NAKo te ' he kaha mahi-tauhohenga e rite ana te rahi engari he ahunga ke, nō reira ka tangohia atu i te whārite.
F – wA - wB = (mA +mB) a
5 – 1 – 3 = (0,1 + 0,3) he
5 – 4 = (0,4) a
1 = (0,4) he
ā = 1 / 0,4
a = 2,5 m/s2
Mā te aroaro o te kaha (F) o te 5 Newton e mahi poutū ana ki runga i ngā poraka e rua ka neke poutū ake ngā poraka e rua me te whakaterenga o te 2,5 m/s.2.
Whakaarohia te poraka A:
Whakamahia te ture tuarua a Newton ki te poraka A:
∑F = ma
NA - wA = mA a
NA – 1 = (0,1)(2,5)
NA - 1 = 0,25
NA = 1 + 0,25
NA = 1,25 Niutona
Ko te kaha noa i raro i te poraka B i runga i te poraka A he 1,25 Newton.
Ko te whakautu tika ko B.
Te Ture Tuatoru a Newton
5. Kia aro ki te kōrero e whai ake nei!
(1) I panaia ngā pāhihi ki mua i te wā i pēhi ohorere ai te pahi, e neke haere tonu ana, ki te pēhi kaha.
(2) Kāore te puranga pukapuka i runga i te kāta e taka ina tōia teretia te kāta.
(3) I te wā e tākaro ana i te papa reti, ina panaia te whenua e te waewae kore utu ki muri, ka paheke whakamua te papa reti.
(4) Ka panaia te hoe poti ki muri, ka neke whakamua te poti.
Ko te kōrero i runga ake nei e hangai ana ki te ture tuatoru a Newton ko...
A. (1) me (2)
B. (1) me (3)
C. (2) me (3)
D. (3) me (4)
Kōrero
(1) Te ture tuatahi a Newton
(2) Te ture tuatahi a Newton
(3) Te ture tuatoru a Newton
(4) Te ture tuatoru a Newton
Ko te whakautu tika ko D.
Pūtake pātai:
Ngā Pātai Whakamātautau Pūtaiao ā-Motu mō te Kura Tuarua/Kura Tuarua Ihirama
Ngā Pātai OSN mō te Ahupūngao o te Kura Tuarua
