Ki te totoro koe i tētahi here rapa, i tētahi potae rapa rānei ki tētahi wāhi, ka totoro. I muri i tō tukunga i te kukū, ka hoki te rapa ki tōna roa taketake. Waihoki, ina totoro koe i tētahi puna, ka totoro. I muri i tō tukunga, ka hoki ki tōna roa taketake. Ka totoro te puna, te rapa rānei ina totorohia, ā, ka hoki anō ki tōna roa taketake i muri i te tukunga o te kukū nā te mea he pīwariwari. Ko te pīwariwari ko te kaha o tētahi mea ki te hoki ki tōna āhua taketake ina tangohia te kaha e pā ana ki a ia.
Kua ngaungau kē koe i te kapia? Ki te tōia e koe te kapia ki ngā ringa e rua, ka roa ake. I muri i tō tukunga i te tō, ka noho tonu te āhua o te kapia, ki te kore, kāore te roa o te kapia e hoki ki tōna āhua taketake. Pērā anō hoki mō te kirihou, te uku, me ētahi atu. Ko ngā mea pēnei i te kapia ngaungau, te kirihou, me te uku ka kiia he mea kirihou. Ka taea hoki e ngā mea pīwariwari pēnei i te puna te huri hei kirihou mēnā ka tōia me te kaha nui, ā, ka nui ake i tō rātou rohe pīwariwari.
Ki te tōia te puna ki te taha matau, ka totoro, ka roa ake (Pikitia 1). Ki te kore e tino nui te kaha kume, ka kitea ko te pikinga o te roa o te puna he rite ki te nui o te kaha kume (F). Ara, ko te nui ake o te kaha kume, ko te nui ake o te pikinga o te roa o te puna. He uara pumau te ōwehenga o te nui o te kaha kume (F) ki te pikinga o te roa o te puna.
He pumau te ōwehenga i waenga i te kaha (F) me te pikinga o te roa o te puna, e tohuhia ana e te pari rite o te kauwhata (ahua 2).
Ko k te pūmau puna, te tauwehenga o te ngāwari o te puna, te ine rānei i te ngāwari o te puna. I kitea tuatahitia tēnei whanaungatanga e Robert Hooke (1635 – 1703) i te tau 1678, nō reira i mōhiotia ai ko te ture a Hooke.
Mena ka nui ake te kaha e pā ana ki te puna i te rohenga rapa o te puna, kātahi ka tangohia te kaha, kāore te roa o te puna e hoki ki tōna roa taketake. Ka pā noa te ture a Hooke ki te rohenga rapa . Ko te rohenga rapa o te puna ko te kaha mōrahi ka taea te pā ki te puna i mua i te hurihanga tuturu o te puna, ā, kāore e taea e te roa o te puna te hoki ki tōna roa taketake. Mena ka piki tonu te kaha, ka pakaru te puna.
Tauira raruraru
1. Ngā Pātai Whakamātautau ā-Motu 2018
Ka herea he pere ki te aho kopere, kātahi ka kumea whakamuri ki te kaha o te 20 N kia totoro te aho kopere ki te tawhiti o te 20 cm. Kāore e arohia te waku hau, ko te taumaha o te pere he 250 karamu, nō reira ko te tere o te pere ina koperea mai i te kopere ko…
Kōrero
E mōhiotia ana:
Te kaha (F) = 20 N
Te pikinga o te roa ( s) = 20 cm = 0,2 m
Taumaha o te pere (m) = 250 karamu = 0,25 kg
Te tere tīmatanga (v o ) = 0 m/s
I pātaihia: Te tere o te pere ina koperea mai i te kopere
Whakautu:
Mahi (W) = huringa o te pūngao nekeneke ( ΔEK)
W = Fs = (20)(0,2) = 4
EK = 1/2 m (vt2 -vo2) = 1/2 m (vt2) = 1/2 (0,25)(vt2) = 1/2 (0,25)(vt2) = 0,125 vt2
W = ΔEK
Fs = 1/2 m ( vt 2 )
4 = 0,125 v t 2
4/0,125 = v t 2
v t 2 = 32
vt = √32
v t = √(16)(2)
v t = 4√2 m/s
