Te whakamahinga o te tiakitanga o te pūngao miihini mō te nekehanga i runga i ngā mata piko – ngā raruraru me ngā otinga

1. Ka paheke iho tētahi poraka 1-kg te taumaha i runga i te mata kōpiko maeneene. Tātaihia te pūngao nekeneke me te tere o te poraka i te mata o raro rawa. Ko te whakaterenga nā te kaha ā-papatipu he 10 m/s ².

Mōhiotia:

Taumaha (m) = 1 kg

Ko te panonitanga o te teitei (h) = 5 m

Te whakaterenga nā te kaha ā-papa (g) = 10 m/s ²

E hiahiatia ana: Te pūngao nekeneke (KE) me te tere o te poraka.

Rongoā:

(a) Pūngao nekeneke

Ko te pūngao ā-pūkaha tīmatanga = te pūngao pūmanawa ā-papa

ME _o = PE = mgh = (1)(10)(5) = 50 Joule

Ko te pūngao miihini whakamutunga = te pūngao nekeneke

ME _t = KE = ½ mv _t ²

Ko te mātāpono o te tiaki i te pūngao ā-pūkaha e kī ana ko te pūngao ā-pūkaha tīmatanga = te pūngao ā-pūkaha whakamutunga:

ME _o = ME _t

PE = KE

50 = KE

Pūngao nekeneke (KE) = 50 Joule.

(b) Te tere o te poraka

Te mātāpono o te tiaki i te pūngao miihini:

Ko te pūngao miihini tīmatanga (ME₂o ₎ = te pūngao miihini whakamutunga ( _ME₂t )

Ko te pūngao pūmanawa ā-papa (PE) = te pūngao nekeneke (KE)

50 = ½ mv ²

2(50) / m = v ²

100 / 1 = v ²

100 = v ²

v = √100

v = 10 m/s

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2. Ka paheke te mea 2-kg ki raro, kāore he waku. He aha te pūngao nekeneke me te tere o te mea i te 2 mita i runga ake i te whenua? Ko te whakaterenga nā te kaha ā-papa he 10 m/s ²

Mōhiotia:

Taumaha (m) = 2 kg

Ko te panonitanga o te teitei (h) = 10 – 2 = 8 m

Te whakaterenga nā te kaha ā-papa (g) = 10 m/s ²

E hiahiatia ana : te pūngao nekeneke (KE) me te tere (v) i te 2 mita i runga ake i te whenua.

Rongoā:

(a) Pūngao nekeneke i te 2 mita i runga ake i te whenua

Ko te pūngao ā-pūkaha tīmatanga = te pūngao pūmanawa ā-papa

ME _o = PE = mgh = (2)(10)(8) = 160 Joule

Ko te pūngao miihini whakamutunga = te pūngao nekeneke

ME _t = KE = ½ mv _t ²

Ko te mātāpono o te tiaki i te pūngao ā-pūkaha e kī ana ko te pūngao ā-pūkaha tīmatanga = te pūngao ā-pūkaha whakamutunga:

ME _o = ME _t

PE = KE

160 = KE

Ko te pūngao nekeneke (KE) i te 2 mita i runga ake i te whenua he 160 Joules.

(b) Te tere o te mea i te mata o raro rawa

Te mātāpono o te tiaki i te pūngao ā-pūkaha:

Ko te pūngao miihini tīmatanga (ME₂o ₎ = te pūngao miihini whakamutunga ( _EM₂t )

Ko te pūngao pūmanawa ā-papa (PE) = te pūngao nekeneke (KE)

160 = ½ mv ²

160 = ½ (2) v ²

160 = v ²

v = √160 = √(16)(10) = 4√10 m/s

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1. Ngā raruraru me ngā otinga mō te mahi i mahia mā te kaha
2. Ngā raruraru me ngā otinga mō te pūngao mahi-nekeneke
3. Ngā raruraru me ngā otinga o ngā mātāpono mahi-pūngao miihini
4. Ngā raruraru me ngā otinga o te pūngao pūmanawa ā-papa
5. Te pūngao pūmanawa o ngā raruraru me ngā otinga o te puna rapa
6. Ngā raruraru hiko me ngā otinga
7. Te whakamahinga o te tiakitanga o te pūngao miihini mō te nekehanga hinga noa
8. Te whakamahinga o te tiakitanga o te pūngao miihini mō te nekehanga ki runga, ki raro hoki i te nekehanga hinga noa.
9. Te whakamahinga o te tiakitanga o te pūngao miihini mō te nekehanga i runga i te mata piko
10. Te whakamahinga o te tiakitanga o te pūngao miihini mō te nekehanga i runga i te papa whakarara
11. Te whakamahinga o te tiaki i te pūngao miihini mō te nekehanga pere