4 Ngā tauira o ngā whakaritenga puna raupapa
1. E rima ngā puna, he 200 N/m te pūmau kaha o ia puna, kua whakaritea kia raupapa. Ko te pūmau puna ōrite o te whakaritenga puna ko…
Kōrero
E mōhiotia ana:
Ko te pūmau o ia puna (k1 = k2 = k3 = k4 = k5) = 200 N/m
I pātaihia: te pūmau puna whakakapinga (k)
Whakautu:
Pūmau puna whakakapinga :
1/k = 1/k1 + 1/k2 + 1/k3 + 1/k4 + 1/k5
1/k = 1/200 + 1/200 + 1/200 + 1/200 + 1/200
1/k = 5/200
k = 200/5
k = 40 Newton/mita
2. E rua ngā puna kua whakaritea pēnei i te whakaaturanga i raro nei. He pūmau k tō ia puna1 = 200 N/m me k2 = 300 N/m. Kei te iri te papatipu 2 kg mai i te puna. Mena ko te whakaterenga nā te kaha ā-papatipu he 10 m/s2 kātahi ka piki ake te roa o te huihuinga puna...
Kōrero
E mōhiotia ana:
Pūmau puna 1 (k)1) = 200 N/m
Pūmau puna 2 (k)2) = 300 N/m
Papatipu o te kawenga (m) = 2 kg
Te whakaterenga nā te kaha ā-papa (g) = 10 m/s2
Te kaha taumaha (w) = mg = (2)(10) = 20 Newton
I pātaihia: te pikinga o te roa whakaritenga raupapa puna (x)
Whakautu:
Pūmau puna whakakapinga :
1/k = 1/k1 + 1/k2
1/k = 1/200 + 1/300 = 3/600 + 2/600 = 5/600
k = 600/5
k = 120 Newton/mita
Te whakanui ake i te roa o te huihuinga puna :
x = F / k = w / k
x = 20 / 120
x = 1/6 mita
Ko te pikinga o te roa o te whakaritenga puna ko te pikinga o te roa katoa o ngā puna e toru.
3. E toru ngā puna ōrite kua whakaritea e whakaaturia ana i raro nei. E whakairihia ana he taumaha 15 Newton mai i te pito o raro o ngā puna, ā, ka roa ake te pūnaha puna mā te 5 cm. Ko te pūmau puna o ia puna ko…
Kōrero
E mōhiotia ana:
Te kaha taumaha (w) = 15 Newton
Te pikinga o te roa o te huihuinga puna = 5 cm = 0,05 mita
I pātaihia: te pūmau o ia puna
Whakautu:
Tatau kpūmau puna whakakapinga mā te whakamahi i te tātai Te ture a Hooke :
k = F / x = w / x
k = 15 / 0,05
k = 300 Newton/mita
Te pumau o ia puna :
1/k = 1/k1 + 1/k2 + 1/k3
1/300 = 1/k + 1/k + 1/k
1/300 = 3/k
k = (3)(300)
k = 900
k = 900 N/m
He ōrite ngā puna e toru, nō reira he ōrite ngā pūmau. Pūmau puna 1 (k1) = pūmau puna 2 (k2) = pūmau puna 3 (k3) = 900 Newton/mita
4. E toru ngā puna me te pūmau o ia puna k kua whakaritea kia raupapa. Ko te pūmau puna whakakotahi ko…
A. 1/5 mano
B. 1/4 k
C. 1/3 k
D. 1/2 mano
E.k
Kōrero:
Te tātai pūmau puna mō te whakaritenga raupapa :
1/kp = 1/k + 1/k + 1/k
Pūmau puna whakakotahi :
1/kp = 3/k
kp = k/3 = 1/3 k
Ko te whakautu tika ko C.
