Ko te waku pumau te kaha waku e pā ana ki ngā mata o ngā mea e pā ana tetahi ki tetahi i te wā kāore ngā mea e neke ana.
E whakaatu ana te Pikitia 1 i tētahi mea e tū ana i runga i tētahi mata papatahi e tōia ana e te kaha F. Mēnā kāore te mea e neke ana, he iti iho te f s i te kaha kukume (F). Mēnā ka whakanuia te kaha kukume, ka neke te mea. Ina tata te mea ki te neke, ka ōrite te rahi o te f s ki te rahi o te kaha kukume (F).
E ai ki te Ture Tuatahi a Newton, kei te okioki tetahi mea mēnā he ōrite te kaha hua, te kaha katoa rānei ki te kore.
Ki te hiahia koe ki te whakatau i te tauwehenga waku pateko, whakamahia te whārite 1.1 b
Ina tata te neke o te mea, ka nui te te kaha waku pūmau mōrahi he ōrite ki te rahi o te kaha pana, te kaha kukume rānei.
Tauira raruraru.
1. Ka tōia he poraka 1 kg e whakatakotoria ana ki runga i tētahi mata papatahi mā te whakamahi i tētahi dynamometer (he taputapu hei ine i te kaha). Ina tata te poraka ki te neke, ka pānuihia e te dynamometer te 2 Newton. Te whakaterenga nā te kaha ā-papa = 10 m/s2Whakatauhia (a) te rahi o te kaha waku (b) te tauwehenga waku
Kōrero
E mōhiotia ana :
Taumaha o te poraka (m) = 1 kg
Te whakaterenga nā te kaha ā-papa (g) = 10 m/s2
Te taumaha o te poraka (w) = mg = (1 kg)(10 m/s)2) = 10 kg m/s2 = 10 Niutona
Te kaha kume (F) = 2 Newton
Whakautu :
(a) Te rahi o te kaha waku pumau (fs)
Ina tata te poraka te neke, ko te rahi o te kaha waku pumau = te rahi o te kaha kume (whakatairitehia te whārite 1.4).
Nō reira, ko te kaha waku pumau (fs) = te kaha kume (F) = 2 Newton
(b) Tauwehenga waku pumau
