He tauira mō te whakamahi i ngā ture a Newton i runga i te papa whāiti (he waku kei reira)

E rua ngā tauira o te whakamahi i ngā ture a Newton ki ngā papa whakarara (he waku kei reira)

1. Ko te taumaha o te poraka he 2 kg, ko te whakaterenga nā te kaha ā-papatipu = 10 m/s², ko te tauwehenga o te waku pūmau me te waku nekeneke he 0,2 me te 0,1. Kei te tū tonu te poraka, kei te neke rānei? Mena kei te neke te poraka, whakatauhia (a) te kaha hua e whakateretere ana i te poraka (b) te rahi me te ahunga o te whakateretere o te poraka!
Kōrero
E mōhiotia ana :
Taumaha (m) = 2 kg
Te whakaterenga nā te kaha ā-papa (g) = 10 m/s²
Tauwehenga waku pūmau = 0,2
Tauwehenga waku pūmau = 0,1
Taumaha o te poraka (w) = mg = (2)(10) = 20 Newton
w_x = w sin 30^o = (20)(0,5) = 10 Ngā Newton
w_y = w cos 30^o = (20)(0,5√3) = 10√3 Ngā Newton
Te kaha noa (N) = w_y = 10√3 Nūtene
Te kaha waku pumau (f_s) = (0,2)(10√3) = 2√3 Ngā Newton
Te kaha waku nekeneke (f_k) = (0,1)(10√3) = √3 Ngā Newton
I pātaihia Kei te tū tonu te poraka, kei te neke rānei? Ki te neke, tātaihia te kaha hua e whakateretere ana i te poraka me te whakateretere o te poraka!

Whakautu :
Kei te okioki te poraka mēnā w_x < f_s, ka neke te poraka mēnā w_x > wh_sNā te mea_x = 10 Newton me f_s = 2√3 Ngā Newton, nō reira ka whakatauhia ko te poraka e neke ana ki raro.
(a) te kaha hua e whakateretere ana i te poraka
Ina neke te poraka, ko te kaha waku e pā ana ki te poraka ko te kaha waku nekeneke (f_k).
(b) te rahi me te ahunga o te whakaterenga o te poraka
Ko te rahi o te whakaterenga o te poraka he 4,15 m/s² ā, ko te ahunga o te whakaterenga o te poraka kei raro.

2. Ko te taumaha o te poraka he 4 kg, ko te whakaterenga nā te kaha ā-papa he 10 m/s². Ko ngā tauwehenga o te waku pūmau me te waku nekeneke ko te 0,4 me te 0,2. Mena ko te rahi o te kaha F ko te 40 Newton, kei te tū tonu te poraka, kei te neke rānei? Mena kei te neke te poraka, tautuhia (a) te kaha hua e whakateretere ana i te poraka (b) te rahi me te ahunga o te whakateretere o te poraka!
Kōrero
E mōhiotia ana :
Taumaha (m) = 4 kg
Te whakaterenga nā te kaha ā-papa (g) = 10 m/s²
Tauwehenga waku pūmau = 0,4
Tauwehenga waku pūmau = 0,2
Taumaha o te poraka (w) = mg = (4)(10) = 40 Newton
w_x = w sin 30^o = (40)(0,5) = 20 Ngā Newton
w_y = w cos 30^o = (40)(0,5√3) = 20√3 Ngā Newton
Te kaha noa (N) = w_y = 20√3 Nūtene
Te kaha waku pumau (f_s) = (0,4)(20√3) = 8√3 Ngā Newton
Te kaha waku nekeneke (f_k) = (0,2)(20√3) = 4√3 Ngā Newton
F = 40 Newton
I pātaihia Kei te tū tonu te poraka, kei te neke rānei? Ki te neke, tātaihia te kaha hua e whakateretere ana i te poraka me te whakateretere o te poraka!
Whakautu :
Ka neke te poraka ki raro mēnā ko F < w_x +f_sKa neke ake te poraka mēnā ka > w te F_x +f_s. F = 40 Newton, w_x = 20 Newton me f_s = 8√3 = 13,6 Newton, nō reira ka whakatauhia ko te poraka e neke ake ana nā te mea he nui ake a F i a w_x +f_s.
(a) te kaha hua e whakateretere ana i te poraka
Ina neke te poraka, ko te kaha waku e pā ana ki te poraka ko te kaha waku nekeneke (f_k).
(b) te rahi me te ahunga o te whakaterenga o te poraka
Ko te rahi o te whakaterenga o te poraka he 1,6 m/s² ā, ko te ahunga o te whakaterenga o te poraka kei runga.

[Ingarihi: Te nekehanga i runga i te papa whakarara me te kaha waku]