Tātai Kaha Noa
Ko te kaha noa tētahi o ngā kaha whakapā tino taketake, ā, he maha ngā wā ka puta i roto i ngā āhuatanga miihini o te ahupūngao. Ka mahi poutū ki te mata o te pānga i waenganui i ngā mea e rua. Ka whakamāramahia e tēnei tuhinga te whakamāramatanga o te kaha noa, te tātai taketake i whakamahia hei tatau, me ōna tono me ngā tauira mahi i roto i te oranga o ia rā.
Te Whakamāramatanga o te Kaha Noa
Ko te kaha noa ko te kaha tauhohenga e puta ana ina pā ana ngā mata e rua tetahi ki tetahi. Ka mahi poutū tēnei kaha ki te mata pa. Ina whakanohoia he mea ki runga i te mata papatahi, ko te kaha noa ko te kaha e whakamahia ana e te mata hei tautoko i te mea. E ai ki te ture tuatoru a Newton, he tauhohenga ōrite engari he rerekē te āhua o ia mahi. Nō reira, ina pēhia e te mea tetahi mata ki te kaha o te kaha ā-papa, ka whakamahia e te mata he kaha ōrite engari he rerekē te āhua, arā, te kaha noa.
Te Tātai Taketake mō te Kaha Noa
Ko te tātai taketake mō te kaha noa e whakawhirinaki ana ki ngā āhuatanga o te pūnaha me te ahunga o ngā kaha e mahi ana. Anei ētahi āhuatanga noa me pēhea te tatau i te kaha noa mō ia āhuatanga.
Ngā Mea i runga i te Mata Papatahi
Mō tētahi mea i runga i tētahi mata papatahi kāore he whakaterenga poutū, he ōrite te kaha noa (\(N\)) ki te kaha taumaha (\(W\)) o te mea. Ko te tātai ko:
\[ N = W = mg \]
Kei hea:
– Ko te kaha noa (Newton, N) te \(N\),
– Ko te \(m\) te papatipu o te mea (kirokaramu, kg),
– Ko te \(g\) te whakaterenga nā te kaha ā-papa (tata ki te 9.8 \(m/s^2\) i runga i te mata o te Ao).
Ngā Mea i runga i te Mata Piko
Mō tētahi mea i runga i tētahi mata piko me te koki piko \(\theta\), he rerekē te kaha noa i te kaha taumaha. I tēnei wā, ko te kaha noa te wāhanga o te kaha taumaha e poutū ana ki te mata piko. Ko te tātai ko:
\[ N = mg \cos \theta \]
Kei hea:
– Ko te \( \theta \) te koki o te piko o te mata e pā ana ki te whakapae.
Ngā Mea i roto i te Ararewa
Ina kei roto i tētahi ararewa tētahi mea e neke ana me te whakaterenga \(a\), ko te kaha noa e pā ana ki te mea ka whakawhirinaki ki te ahunga me te rahi o te whakaterenga o te ararewa. Ko te tātai mō te kaha noa i roto i tētahi ararewa ko:
\[ N = m(g \pm a) \]
Ka whakamahia te tohu tāpiri (+) mēnā ka neke te ararewa ki runga (ka whakanui ake i te whakaterenga ā-papa) ā, ka whakamahia te tohu tango (-) mēnā ka neke te ararewa ki raro (ka whakaiti i te whakaterenga ā-papa).
Te Whakamahinga o te Kāhua Noa i roto i te Oranga o Ia Rā
Ehara i te mea he mea nui te kaha noa i roto i ngā ariā ariā anake, engari he maha hoki ngā whakamahinga mahi i roto i te oranga o ia rā. Anei ētahi tauira:
Te kawe waka
I roto i ngā waka pērā i ngā motuka, he mea nui te kaha noa i waenga i te potae me te mata o te rori hei tatau i te waku, ka pā ki te kukume me te pumau o te waka. He iti iho te kaha noa o ngā potae kua nui rawa te pupuhi, ka pā kino ki te haumaru o te taraiwa.
Te Hanga Whare
I roto i te hanganga, me tātari ngā kaha noa i waenga i ngā wāhanga hanganga pēnei i ngā kurupae me ngā pou hei whakarite i te pumau me te haumaru o te whare. He mea nui anō hoki ēnei kaha ki te hoahoa i te turanga o te whare hei tautoko i te taumaha o te hanganga i runga ake.
Peralatan Rumah Tangga
He maha ngā taputapu o te whare, pērā i ngā pauna o te kīhini, e whakamahi ana i te ariā o te kaha noa hei ine i te taumaha o ngā mea. Ina whakatakotoria he mea ki runga i te pauna, mā te kaha noa e pā ana ki te mata o te pauna ka puta he pānui o te taumaha o te mea.
Hākinakina
I ngā hākinakina pēnei i te piki toka, ko te kaha noa i waenganui i ngā ringaringa, i ngā waewae rānei o te kaipiki me te mata toka te mea e whakatau ana i tōna kaha ki te pupuri i a ia anō i te kaha ā-papa. Mā ngā hū motuhake he kapu kua hangaia hei whakanui ake i te kaha noa ka āwhina i ngā kaipiki kia pai ake te pupuri.
Tauira o te Tātaitanga o te Kaha Noa
Me titiro tātou ki ētahi tauira o ngā tataunga kaha noa i roto i ngā āhuatanga rerekē hei whakamārama i tō tātou māramatanga.
Tauira 1: Ngā Mea i runga i te Mata Papatahi
Ka whakatakotoria he pukapuka he 2 kg te taumaha ki runga i tētahi tēpu papatahi. Tātaihia te kaha noa e pā ana ki te pukapuka.
E mōhiotia ana:
– Taumaha (\(m\)) = 2 kg,
– Te whakaterenga nā te kaha ā-papa (\(g\)) = 9.8 \(m/s^2\).
Mā te whakamahi i te tātai kaha noa:
\[ N = mg \]
\[ N = 2 \, \text{kg} \times 9.8 \, \text{m/s}^2 \]
\[ N = 19.6 \, \kuputuhi{N} \]
Nō reira, ko te kaha noa e pā ana ki te pukapuka he 19.6 N.
Tauira 2: He mea kei runga i te mata piko
Kei runga i tētahi papa whakarara te pouaka, e 5 kg te taumaha, e hanga ana i tētahi koki 30° ki te taha whakapae. Tātaihia te kaha noa e pā ana ki te pouaka.
E mōhiotia ana:
– Taumaha (\(m\)) = 5 kg,
– Te whakaterenga nā te kaha ā-papa (\(g\)) = 9.8 \(m/s^2\),
– Koki piko (\(\theta\)) = 30°.
Mā te whakamahi i te tātai kaha noa mō te mata hianga:
\[ N = mg \cos \theta \]
\[ N = 5 \, \text{kg} \times 9.8 \, \text{m/s}^2 \times \cos 30° \]
\[ N = 5 \times 9.8 \times \frac{\sqrt{3}}{2} \]
\[ N = 5 \whakareatia 9.8 \whakareatia 0.866 \]
\[ N \tata ki te 42.35 \, \kuputuhi{N} \]
Nō reira, ko te kaha noa e pā ana ki te pouaka he 42.35 N pea.
Tauira 3: Ngā Taonga i roto i te Ararewa
Kei roto i tētahi ararewa te tangata he 70 kg te taumaha, e neke ake ana me te whakaterenga o te 2 \(m/s^2\). Tātaihia te kaha noa e pā ana ki te tangata.
E mōhiotia ana:
– Taumaha (\(m\)) = 70 kg,
– Te whakaterenga nā te kaha ā-papa (\(g\)) = 9.8 \(m/s^2\),
– Te whakaterenga o te ararewa (\(a\)) = 2 \(m/s^2\).
Mā te whakamahi i te tātai kaha noa i roto i tētahi ararewa e neke ana ki runga:
\[ N = m(g + a) \]
\[ N = 70 \, \kw{kg} \times (9.8 \, \kw{m/s}^2 + 2 \, \kw{m/s}^2) \]
\[ N = 70 \whakareatia ki te 11.8 \]
\[ N = 826 \, \kuputuhi{N} \]
Nō reira, ko te kaha noa e pā ana ki te tangata ko 826 N.
Whakamutunga
Ko te kaha noa he ariā taketake i roto i te ahupūngao e whakaahua ana i te kaha tauhohe e mahi poutū ana ki te mata o te pa i waenga i ngā mea e rua. Ka rerekē te tātai taketake mō te kaha noa i runga i ngā āhuatanga o te pūnaha, pērā i ngā mea i runga i te mata papatahi, i te mata piko, i roto rānei i te ararewa e neke ana. Mā te mārama pai ki te kaha noa ka taea e tātou te tātari me te hoahoa i ngā pūnaha mīhini kia pai ake te whai hua, ahakoa i roto i te horopaki o te kawe waka, te hanga, me ētahi atu tono o ia rā. Mā ngā tauira tatau kua whakaratohia, ka taea e tātou te kite me pēhea te whakamahi i tēnei ariā i roto i ngā āhuatanga mahi maha hei whakarite i te pumau, te whai hua, me te haumaru.
