1. Ka wiri tetahi mea me te auau o te 5 Hz ki te taha matau me te taha maui. Ka neke te mea mai i te pūwāhi taurite ki te nekehanga mōrahi ki te taha matau. Tātaihia te wā e hiahiatia ana hei tae atu ki te nekehanga mōrahi ki te taha matau i ngā wā tekau mā tahi.
A. 2.05
B. 2.20
C. 2.25
D. 2.50
Mōhiotia:
Auautanga (f) = te nui o te wiri mō te 1 hēkona = 5 Hz
Wā (T) = te wā hei mahi i te wiri kotahi = 1/f = 1/5 = 0.2 hēkona
E hiahiatia ana: Te wā e hiahiatia ana hei whakatutuki i te nekehanga mōrahi i ngā wā tekau mā tahi ki te taha matau
Rongoā:
Te tauira o te wiri o te mea:
(1 wiri): B → C → B → A → B
Mō te wiri kotahi, e whā ngā wiri e mahia ana e te mea, arā, B ki C, C ki B, B ki A, A ki B. Ko te wā e hiahiatia ana mō te wiri kotahi ko 0.2 hēkona / 4 = 0.05 hēkona.
Ko te wā e hiahiatia ana hei whakatutuki i te nekehanga mōrahi i ngā wā tekau mā tahi whaka te taha matau = (10 x 0.2 hēkona) + 0.05 hēkona = 2 hēkona + 0.05 hēkona = 2.05 hēkona.
Ko te whakautu tika ko A.
2. Ka whakairihia he puna ki tētahi mea, ā, ka wiriwirihia. Kia rua te auau wiri i te auau wiri taketake, ka hurihia te papatipu o te mea ki…
A. e rua te taumaha o te kawenga taketake
B. e whā ngā wā o te taumaha o te kawenga taketake
C. te haurua o te wā taumaha kawenga
D. te hauwhā o te taumaha kawenga taketake
Rongoā:
Ko te whārite o te auau o te wiri o te puna:
f = auau, k = pūmau, m = papatipu o te mea
Te auau (f) o te wiri o te puna mēnā ko k = 1 te wā, ko m = 1 te wā:
Kia rua te auau o te wiri o te puna i te papatipu (m) ka hurihia ki te 0.25 ngā wā, ki te 1/4 rānei:
Ko te whakautu tika ko D.
3. Kei te whakairihia he puna me te pūmau k = 1000 N/m ki tētahi mea he 400 karamu te taumaha. Ka tōia te mea ki te taha matau tae noa ki te 5 cm, kātahi ka tukuna, kia rite ai te mea ki ngā harmonika oscillating māmā . Tātaihia te kaha me te auau o te oscillation o te mea.
Mōhiotia:
Te pūmau o te puna (k) = 1000 N/m
Taumaha o te mea (m) = 400 karamu = 0.4 kg
Te whānui (Δx) = 5 cm = 0.05 m
E hiahiatia ana: Te whānui me te auau o ngā wiriwiri
Rongoā:
Ko te kaha o te wiri o te puna = Δx = 5 cm.
Te auau o ngā wiriwiri:
Ko te whakautu tika ko B.
