7 Ngā Pātai Pakihi
1. Tirohia te pikitia e whai ake nei!
Ko te nui o te mahi i mahia ki te poraka he...
A. 3 Joules
B. 8 Joules
C. 16 Joule
D. 48 Joule
Kōrero
E mōhiotia ana:
Te Kaha (F) = 12 Newton
Nekehanga (s) = 4 mita
I pātaihia: Ngā Mahi (W)
Whakautu:
I te ahua i runga ake nei, ko te nekehanga o te mea kei te ahunga kotahi me te kaha. Ko te tātai mahi mō tēnei take ko:
W = Fs = (12 Newton)(4 mita) = 48 mita Newton = 48 Joules
Ko te whakautu tika ko D.
2. Ka panaia tētahi poraka rakau ki te kaha o te 200 N kia neke ai i te tawhiti o te 2 m, ko te mahi i mahia e te poraka rakau ko...
A. 20 J
B. 100 J
C. 200 J
D. 400 J
Kōrero
E mōhiotia ana:
Te Kaha (F) = 200 Newton
Nekehanga (s) = 2 mita
I pātaihia: Ngā Mahi (W)
Whakautu:
Pakihi:
W = Fs
W = (200 Newton)(2 mita)
W = 400 mita Newton
W = 400 Joule
Ko te whakautu tika ko D.
3. Tirohia te pikitia!
E hiahia ana te taraiwa o te waka sedan ki te whakatū i tana waka kia 0,5 m te tawhiti ki mua i tētahi taraka i te tīmatanga he 10 m te tawhiti mai i te waka sedan. E hia te kaha e hiahiatia ana mō te waka sedan?
A. 525 J
B. 500 J
C. 495 J
D. 475 J
Kōrero
E mōhiotia ana:
Te nekehanga (s) = 10 mita – 0,5 mita = 9,5 mita
Te Kaha (F) = 50 Newton
I pātaihia: Ngā Mahi (W)
Whakautu:
Tātai pakihi:
W = Fs
W = (50 Newton)(9,5 mita)
W = 475 mita Newton
W = 475 Joule
Ko te whakautu tika ko D.
4. Tirohia te pikitia!
Ko te nui o te kaha i mahia e Andi rāua ko Toni ki te neke i te motuka kia 4 mita mēnā ko ngā kaha o ngā tamariki tokorua he 50 N me te 70 N ia...
A. 80 joule
B. 200 joule
C. 280 joule
D. 480 joule
Kōrero
E mōhiotia ana:
Nekehanga (s) = 4 mita
Te kaha hua (F) = 50 Newton + 70 Newton = 120 Newton
I pātaihia: Ngā Mahi (W)
Whakautu:
Pakihi:
W = Fs = (120 Newton)(4 mita) = 480 mita Newton = 480 Joules
Ko te whakautu tika ko D.
5. Ka tōia e te taraiwa tētahi waka kua tū, e ai ki te pikitia, kia neke ai te waka i te tawhiti o te 1.000 cm. Ko te nui o te mahi i mahia ko….
A. 250 Joules
B. 1.000 Joules
C. 2.500 Joule
D. 250.000 Joule
Kōrero
E mōhiotia ana:
Whakahuatia ngā waeine katoa o te Pūnaha Ao Whānui
Te Kaha (F) = 250 Newton
Nekehanga (s) = 1000 cm = 1000/100 mita = 10 mita
Pātai: Te nui o te kaha (W)
Whakautu:
Tātai pakihi:
W = Fs = (250 Newton)(10 mita) = 2500 mita Newton = 2500 Joules
Ko te whakautu tika ko C.
6. Tirohia te pikitia e whai ake nei mō te nekehanga o ngā mea!
Mena ko te mahi i mahia e ēnei kaha ki runga i tētahi mea he 375 Joules, ka taea e te mea te neke i tētahi tawhiti...
A. 7,5 mita
B. 15 mita
C. 22,5 mita
D. 25 mita
Kōrero
E mōhiotia ana:
Mahi (W) = 375 Joules
Te kaha hua ( ΣF) = 40 N + 10 N – 25 N = 25 Newton (ki te taha matau)
I pātaihia: Te nekehanga
Whakautu:
Tātai pakihi:
W = Fs
Te nekehanga:
s = W / F = 375 Joule / 25 Newton
s = 15 mita
Ko te whakautu tika ko B.
7. Ko ngā mahi a ētahi o ngā tamariki i raro nei kāore e uru ki te mahi pakihi ko...
A. te pana i te kāreti mītiporo kia 10 mita
B. te pana i tētahi waka kua tū kia neke ra ano
C. te pana i tētahi pakitara totoka kia werawera koe
D. E eke pahikara ana mai i te kāinga ki te kura
Kōrero
Tātai pakihi:
W = ΣFs
Ngā Mōhiotanga: W = te kaha, te mahi rānei, F = te kaha, s = te nekehanga
E ai ki te tātai i runga ake nei, he mahi kei reira mēnā he kaha, ā, he nekehanga kei reira (he nekehanga).
Ko te whakautu tika ko C.
Pūtake pātai:
Ngā Pātai Whakamātautau Pūtaiao ā-Motu mō te Kura Tuarua/Kura Tuarua Ihirama
