Mena he kaha hua kei runga i tētahi mea he papatipu m, ka neke te mea i roto i te rārangi tika me te whakaterenga a. Ko te whanaungatanga i waenga i te kaha hua, te papatipu me te whakaterenga ka whakaaturia mā te whārite:
Koinei te whārite o te ture tuarua a Newton i akohia i te akomanga X.
Ko te rahinga ā-tinana i roto i te nekehanga hurihuri e ōrite ana ki te kaha hua i roto i te nekehanga tika ko te iahiko o te kaha hua . Ko te rahinga ā-tinana i roto i te nekehanga hurihuri e ōrite ana ki te papatipu i roto i te nekehanga tika ko te iahiko o te korekore . Ko te rahinga ā-tinana i roto i te nekehanga hurihuri e ōrite ana ki te whakaterenga i roto i te nekehanga tika ko te whakaterenga koki.
Whakaarohia tētahi mea e neke poutū ana ki runga kia tae rā anō ki tōna teitei mōrahi, kātahi ka neke ki raro ki tōna tūranga taketake. I a ia e neke poutū ana ki runga i te tawhiti h, kei te taha kē te kaha o te papatipu i te nekehanga o te mea. Nā te mea kei te taha kē i te nekehanga o te mea, ka mahi kino te kaha o te papatipu ki te mea.

Ki te hiahia koe ki te whakatau i te kaha waku pūmau, whakamahia te whārite 1.5 a. Ki te hiahia koe ki te whakatau i te tauwehenga waku nekeneke, whakamahia te whārite 1.5 b.
Kōrero