Taitara: Te Mārama ki ngā Pūtake Oro: Ngā Tauira Pātai me te Kōrero
Pendahuluan
He ngaru miihini te oro e horapa ana i roto i tētahi reo pērā i te hau, te wai, ngā mea totoka rānei. He mea nui tēnei āhuatanga ki te oranga o ia rā, mai i te whakawhitiwhiti kōrero a te tangata me te pārekareka ki te puoro ki ngā tono hangarau pērā i te sonar me te ultrasound. I roto i tēnei tuhinga, ka tūhuratia e mātou ngā ariā e pā ana ki ngā pūtake oro mā roto i ngā tauira rapanga hei āwhina i tō mātou māramatanga.
Te Ariā Taketake o ngā Pūtake Oro
I mua i te ruku ki ngā tauira raruraru, me arotake poto tātou i te ariā taketake o ngā pūtake oro. Ka puta te oro i te wiri o tētahi mea, ā, he maha ngā āhuatanga nui hei mārama:
1. Auautanga: Te maha o ngā wiri e puta mai ana i tētahi pūtake oro ia hekona, e inehia ana i roto i te Hertz (Hz). Ko te auautanga te whakatau i te teitei o te oro.
2. Te whānui: Te rahi o ngā wiri mai i tētahi pūtake oro. E pā tika ana te whānui ki te kaha, ki te ngawari rānei o te oro.
3. Tere o te Oro: Ka rerekē te tere o te oro i runga i te reo. Hei tauira, ka tere ake te haere o te oro i roto i te wai i te hau.
4. Roangaru: Te tawhiti i waenganui i ngā tihi e rua o te ngaru oro.
Tauira o ngā Pātai Pūtake Oro
Me matapaki tātou i ētahi tauira pātai kia pai ake ai te mārama ki te ariā o ngā pūtake oro.
Pātai 1: Ngā Pūtake Oro me te Auautanga
Ka puta he oro i te marau whakaōrite me te auau o te 440 Hz. Mena ko te tere o te oro i te rangi he 340 m/s, he aha te roangaru o te oro e puta mai ana i te marau whakaōrite?
Kōrero:
Ka taea te tatau i te roangaru mā te whakamahi i te tātai:
\[ \lambda = \frac{v}{f} \]
Ko \( \lambda \) te roanga ngaru, ko \( v \) te tere o te oro, ā, ko \( f \) te auau.
Whakauruhia ngā uara kei a mātou:
\[ \lambda = \frac{340 \, \text{m/s}}{440 \, \text{Hz}} = 0.7727 \, \text{m} \]
Nō reira, ko te roanga ngaru o te oro i whakaputaina ko 0.7727 mita.
Pātai 2: Te Awhe me te Kaha o te Oro
E rua ngā pūtake oro ōrite ka puta he ngaru e rua, he rua ngā kaha o ia ngaru. Mēnā ka honoa ēnei ngaru e rua, he aha te kaha mōrahi ka taea te whakaputa?
Kōrero:
Ina honoa ngā ngaru e rua he rite te kaha me te āhua, ko te kaha mōrahi ka puta ko te tapeke o ō rāua kaha. Nō reira:
Te whānui mōrahi = 2 + 2 = 4 waeine.
Pātai 3: Pānga Doppler
E 30 m/s te tere o te waka tūroro e whakatata atu ana ki tētahi kaihaerere e tū ana. Mēnā ko te auau o tana haona he 700 Hz, ā, ko te tere o te oro i te rangi he 340 m/s, he aha te auau ka rangona e te kaihaerere?
Kōrero:
Whakamahia te tātai pānga Doppler mō tētahi pūtake e whakatata ana ki tētahi kaiwhakarongo:
\[ f' = f \left( \frac{v + v_o}{v – v_s} \right) \]
I konei, ko \( f' \) te auau e kitea ana, ko \( v \) te tere o te oro i te rangi, ko \( v_o \) te tere o te kaiwhakarongo (0 m/s nā te mea e tū ana te kaihaerere), ā, ko \( v_s \) te tere o te pūtake (te waka tūroro).
\[ f' = 700 \, \kākau{Hz} \left( \frac{340 \, \kākau{m/s} + 0 \, \kākau{m/s}}{340 \, \kākau{m/s} – 30 \, \kākau{m/s}} \right) \]
\[ f' = 700 \, \text{Hz} \left( \frac{340}{310} \right) \]
\[ f' = 768.39 \, \kuputuhi{Hz} \]
Nō reira, ko te auau e rangona ana e te kaihaerere he 768.39 Hz pea.
Pātai 4: Te Whakaohooho
He 0.85 mita te roa o tētahi ngongo haruru tuwhera. Mēnā ko te tere o te oro i te rangi he 340 m/s, he aha te auau taketake o tēnei haruru?
Kōrero:
Mō tētahi ngongo tuwhera, ka taea te tatau i te auau taketake mā te whakamahi i te tātai:
\[ f = \frac{v}{2L} \]
Ko \( L \) te roa o te ngongo.
\[ f = \frac{340 \, \text{m/s}}{2 \times 0.85 \, \text{m}} \]
\[ f = 200 \, \kuputuhi{Hz} \]
Nō reira, ko te auau taketake o te ngongo haruru he 200 Hz.
Whakamutunga
He mea nui te mārama ki ngā pūtake oro me ngā āhuatanga e pā ana ki tēnei mea, pērā i te auau, te kaha, te tere, me te pānga Doppler, i roto i te ahupūngao o te oro. E whakaatu ana ngā tauira raruraru i runga ake nei i te whakamahinga o ēnei ariā i roto i ngā āhuatanga rerekē. Mā te ako me te mahi i ēnei raruraru, ka taea e tātou te whakahōhonu ake i tō tātou māramatanga ki te mahi a te oro i tō tātou taha. Me mahi tonu me te tūhura i ngā rauemi rerekē hei whakapakari i tō mōhiotanga ki te oro.
