1. Ka whiua e te tangata tētahi kōhatu 1-kg ki runga i te tere 2 m/s i a ia e tū ana i te taha o te pari kia taka ai te kōhatu ki te take o te pari 40 mita i raro iho. He aha te pūngao nekeneke o te kōhatu i te 10 mita i runga ake i te whenua? Te whakaterenga nā te kaha ā-papatipu g = 10 m/ s2.
Mōhiotia:
Taumaha (m) = 1 kg
Te tere tīmatanga (v o ) = 2 m/s
Te panonitanga o te teitei = 40 – 10 = 30 mita
Te whakaterenga nā te kaha ā-papa (g) = 10 m/s 2
E hiahiatia ana: te kaha nekeneke o te kōhatu i te 10 mita i runga ake i te whenua
Rongoā:
Te pūngao miihini tuatahi
Ko te pūngao pūmanawa ā-papa tuatahi (EP) = mgh = (1)(10)(30) = 300 Joules
Ko te pūngao nekeneke tīmatanga (KE) = ½ mv o 2 = ½ (1)(2) 2 = ½ (4) = 2 Joule
Ko te pūngao miihini tuatahi = te pūngao pūmanawa ā-papa tuatahi + te pūngao nekeneke tuatahi = 300 + 2 = 302 Joule.
Te pūngao miihini whakamutunga
Ko te pūngao miihini whakamutunga = te pūngao nekeneke whakamutunga = te pūngao pūmanawa ā-papa tuatahi + te pūngao nekeneke tuatahi = 300 + 2 = 302 Joule.
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2. Ka whiua e te tangata tētahi mea 1-kg ki runga ki te rangi me te tere tīmatanga o te 10 m/s. Tātaihia (a) te pūngao pūmanawa ā-papa i te teitei mōrahi (b) te teitei mōrahi.
Ko te whakaterenga nā te kaha ā-papa he 10 m/s 2
Mōhiotia:
Taumaha (m) = 1 kg
Te tere tīmatanga (v o ) = 10 m/s
Te whakaterenga nā te kaha ā-papa (g) = 10 m/s 2
E hiahiatia ana : te pūngao pūmanawa ā-papa i te teitei mōrahi me te teitei mōrahi
Rongoā:
(a) te pūngao pūmanawa ā-papa i te teitei mōrahi
Te pūngao miihini tuatahi:
Ko te pūngao miihini tuatahi (ME) = te pūngao nekeneke tuatahi (KE) = ½ mv o 2 = ½ (1)(10) 2 = ½ (100) = 50 Joule.
Te pūngao miihini whakamutunga:
Ko te pūngao miihini whakamutunga (ME) = te pūngao pūmanawa ā-papa (PE)
Te mātāpono o te tiaki i te pūngao miihini:
Ko te pūngao miihini tuatahi = te pūngao miihini whakamutunga
KE = PE
50 = PE
Ko te pūngao pūmanawa ā-papa he 50 Joule.
(b) Te teitei mōrahi
PE = mgh
50 = (1)(10) hāora
50 = 10 hāora
h = 50 / 10 = 5 mita
Ko te teitei mōrahi he 5 mita i runga ake i te whenua.
[wpdm_package id='1174′]
- Ngā raruraru me ngā otinga mō te mahi i mahia mā te kaha
- Ngā raruraru me ngā otinga mō te pūngao mahi-nekeneke
- Ngā raruraru me ngā otinga o ngā mātāpono mahi-pūngao miihini
- Ngā raruraru me ngā otinga o te pūngao pūmanawa ā-papa
- Te pūngao pūmanawa o ngā raruraru me ngā otinga o te puna rapa
- Ngā raruraru hiko me ngā otinga
- Te whakamahinga o te tiakitanga o te pūngao miihini mō te nekehanga hinga noa
- Te whakamahinga o te tiakitanga o te pūngao miihini mō te nekehanga ki runga, ki raro hoki i te nekehanga hinga noa.
- Te whakamahinga o te tiakitanga o te pūngao miihini mō te nekehanga i runga i te mata piko
- Te whakamahinga o te tiakitanga o te pūngao miihini mō te nekehanga i runga i te paparangi piko
- Te whakamahinga o te tiaki i te pūngao miihini mō te nekehanga pere
