Mahi whatunga Pūngao pūmanawa ā-papa Pūngao nekeneke – Ngā Raru me ngā Otinga

4 Mahi kupenga Pūngao pūmanawa ā-papa Pūngao nekeneke – Ngā Raru me ngā Otinga

1. He mea 5-kg te taumaha kei te teitei o te 10 mita i runga ake i te whenua. Whakaterenga na te kaha o te kaha he 10 m/s²He aha te mahi Me pēhea te mahi ki te mea hei nuku ake i te mea ki te teitei o te 15 mita i runga ake i te whenua?

Mōhiotia:

Mass o te mea (m) = 5 kg

Teitei (h) = 10 mita

Te whakaterenga nā te kaha ā-papa (g) = 10 m/s²

Hiahia: I mahia he mahi ki te mea kia nekehia ake ki runga, kia 15 mita te teitei i runga ake i te whenua.

Rongoā:

W = F d = wh = mgh

W = mahi, F = kaha, d = Tuhinga, w = taimaha, h = teitei, m = papatipu, g = whakaterenga nā te kaha ā-papatipu

Ngā mahi i mahia ki te mea:

W = mgh = (5 kg)(10 m/s)²)(10 mita) = 500 kg mita²/s² = 500 Joule

2. E neke ana tētahi mea 2-kg te taumaha i runga i tētahi mata whakapae maeneene me te tere o te 2 m/s. Mena ko te tere whakamutunga o te mea he 5 m/s. He aha te mahi i mahia ki runga i te mea?

Mōhiotia:

Papatipu o te mea (m) = 2 kg

Te tere tīmatanga (v_o) = 2 m/s

Te tere whakamutunga (v_t) = 5 m/s

Hiahia: Te mahi i mahia ki te mea

Rongoā:

te te mātāpono pūngao mahi-nekeneke e kī ana ko te mahi kupenga i mahia ki tētahi mea he rite ki te huringa o te mahi a te mea te kaha kinetic.

W = ΔKE = KE₂ – KI₁ = 1/2 mv_t² – 1/2 mv_o² = 1/2 m (v_t² -v_o²) = 1/2 (2)(5²-2²) = (1)(25-4) = 21 Joule

3. He mea e 10-kg te taumaha i te tīmatanga i runga i te papa maeneene. I muri i te pana i roto i te 3 hēkona, ka tere te mea i te 2 m/s²He aha te mahi i mahia ki te mea?

Mōhiotia:

Taumaha (m) = 10 kg

Te tere tīmatanga (v_o) = 0 (i te tīmatanga i te okiokinga)

Wā wā (t) = 3 hēkona

Whakaterenga (a) = 2 m/s²

E hiahiatia ana: Mahi (W)

Rongoā:

Tuatahi, whakatauhia te tawhiti mā te whakamahi i te whārite o te whakaterenga pumau nekehanga.

d = v_o t + ½ i² = (0)(3) + ½ (2)(3)²

d = 0 + (1)(9) = 9

Ngā mahi i mahia ki te mea:

W = F s = (ma)(d) = (10)(2)(9) = 180 Joule

4. He poraka he 1.5 kg te taumaha i whakaterea ake e te kaha pumau F = 15 N i runga i te papa whakarara e whakaaturia ana i te pikitia i raro nei. Ko te whakaterenga nā te kaha ā-papa he 10 m/s² ā, kāore he waku i waenganui i ngā poraka me papa whakararaHe aha te mahi kupenga i mahia ki te mea?

Mōhiotia:

Taumaha o te poraka (m) = 1.5 kg

Te whakaterenga nā te kaha ā-papa (g) = 10 m/s²

Taumaha o te poraka (w) = mg = (1.5)(10) = 15 Newton

Te Kaha (F) = 15 Newton

Hiahia: Ka mahia te mahi kupenga ki runga i te mea

Rongoā:

E rua ngā kaha e mahi ana i runga i te poraka. Tuatahi, he kaha e whakarara ana ki te nekehanga o te poraka, arā, ko te Kaha F. Tuarua, ko te wāhanga whakapae o te taumaha o te poraka (w_x).

Te mahi i mahia mā te kaha (F):

W₁ = Fs = (15 N)(2 m) = 30 N m = 30 Joules

Te mahi i mahia e te wāhanga whakapae o te taumaha (w_x):

W₂ =w_x s = (w sin 30^o)(2 m) = (15 N)(1/2)(2 m) = 15 N m = 15 Joule

Ngā mahi whatunga i mahia ki te mea:

W_kupenga =W₁ - W₂ = 30 J – 15 J = 15 Joule

1. He aha te ariā mahi-pūngao e pā ana ki te mahi kupenga me te pūngao nekeneke?
   • WhakautuE ai ki te ariā mahi-pūngao, ko te mahi kupenga i mahia ki runga i tētahi mea he rite ki te huringa o tōna pūngao nekeneke. Mā te pāngarau: Wnet​=ΔKE.
2. Ki te hiki koe i tētahi mea ki tētahi teitei, kātahi ka pupuri i taua mea ki reira, e hia te nui o te mahi e mahia ana e koe ki taua mea i a koe e pupuri ana i a ia kia tū tonu?
   • WhakautuI a koe e pupuri ana i te mea kia tū, kāore he mahi e mahia ana e koe ki runga nā te mea kāore he nekehanga. Ko te mahi e tautuhia ana ko te kaha e whakareatia ana te nekehanga i te ahunga o te kaha, nō reira, ko te kore nekehanga he tikanga kāore he mahi.
3. He aha te pūngao pūmanawa ā-papa o tētahi mea i te taumata whenua?
   • WhakautuKo te kaha pūmanawa ā-papa o tētahi mea i te taumata whenua ka kiia he kore. He whanaunga te kaha pūmanawa ā-papa, ā, ko te taumata whenua te pūwāhi tohutoro noa.
4. Me pēhea te hurihanga o te pūngao nekeneke o tētahi mea mēnā ka takiruahia tōna tere?
   • WhakautuHe rite te kaha nekeneke ki te tapawhā o te tere. Mēnā ka takiruahia te tere o tētahi mea, ka piki ake tōna kaha nekeneke mā te whā tau.
5. Āhea te wā ka eke te kaha pūmanawa ā-papa o tētahi mea e hinga ana ki te taumata teitei rawa?
   • WhakautuKo te kaha pūmanawa ā-papa o tētahi mea e hinga ana ka eke ki te mōrahi i mua tata tonu i tōna tīmatanga ki te hinga, arā, ina tae ki tōna wāhi teitei rawa atu i runga ake i te whenua (te pūwāhi tohutoro rānei).
6. I te korenga o te ātete hau, me pēhea te whanaungatanga i waenga i te pūngao pūmanawa i ngaro me te pūngao nekeneke i riro mai i tētahi mea e hinga noa ana?
   • WhakautuKi te kore he ātete hau, ka ōrite te pūngao pūmanawa e ngaro ana i tētahi mea e hinga noa ana ki te pūngao nekeneke e riro mai ana. He hua tika tēnei nō te tiakitanga o te pūngao miihini.
7. Ka ahatia te pūngao pūmanawa ā-papa o tētahi mea mēnā ka hikitia kia rua tōna teitei taketake i runga ake i te whenua?
   • WhakautuHe rite te kaha pūmanawa ā-papa ki te teitei. Mēnā ka hikitia tētahi mea ki te rua o tōna teitei taketake, ka rua tōna kaha pūmanawa ā-papa.
8. Āhea ka oti te mahi kupenga ki runga i te mea kore?
   • WhakautuKo te mahi kupenga i mahia ki tētahi mea he kore ina ko te tapeke o te mahi a ngā kaha katoa e pā ana ki taua mea he kore, he rite tonu rānei, ina kāore he huringa o te pūngao nekeneke o te mea.
9. Mena kei te neke tetahi mea i te tere pumau, he aha te mea ka taea te whakatau mō te mahi kupenga i mahia ki runga i taua mea i runga i tētahi tawhiti kua whakaritea?
   • WhakautuMena kei te neke te mea i te tere pumau, ko te tikanga kāore he whakaterenga, nō reira kāore he kaha kupenga e pā ana ki a ia. Nō reira, ko te mahi kupenga i mahia ki te mea i runga i tētahi tawhiti ka kore.

10. He aha i nui ake ai te pūngao pūmanawa ā-papa o tētahi mea i te teitei teitei ahakoa kei tawhiti atu i te pokapū o Papatūānuku?

    • WhakautuKo te pūngao kaha ā-papa e ahu mai ana i te tūranga o tētahi mea e pā ana ki tētahi pūwāhi tohutoro (ko te mata o te Ao te nuinga) me te kaha o te kaha ā-papa e pā ana ki taua mea. He teitei ake te mea i te teitei i runga ake i tēnei pūwāhi tohutoro, ko te tikanga kua neke atu ki te taha o te kaha ā-papa ki taua tūranga. Nō reira, he pūngao kua rongoatia e ia nā tōna tūranga, ā, ko tēnei pūngao kua rongoatia ko tōna pūngao kaha ā-papa.