9 Ngā Tauira o ngā Pātai Papa Hinga
Akohia ngā rauemi mō ngā ture a Newton , te kaha noa me te kaha waku kia pai ake ai tō mārama ki te matapakinga o tēnei pātai.
1. Ka tukuna he poraka 5 kg te taumaha i runga i tētahi papa whakarara maeneene e whakaaturia ana i te pikitia! (g = 10 ms −2 me te tg 37 o = 3/4). Ko te whakaterenga o te poraka ko...
A. 4,5 ms-2
B. 6,0 ms −2
C. 7,5 ms −2
D. 8,0 ms −2
E. 10,0 ms −2
Kōrero
E mōhiotia ana:
m = 5 kg, karamu = 10 m/ s2
w = mg = (5)(10) = 50 N
te roa o te taha raro = 4
te roa o te taha poutū = 3
Nā te mea ko te taha raro = 4, ā, ko te taha poutū = 3, ko te hypotenuse = 5. Ka taea e koe te whakamatau mā te whakamahi i te tātai Pythagoras.
Pātai: te whakaterenga o te poraka (a)?
Whakautu:
Ko te kaha e neke ai te poraka ko w x . He maeneene te papa whakarara, nō reira kāore he waku.
wx = w hara θ = (w)(taha poutū / taha whakarara) 
wx = (50)(3/5 )
wx = 30 Newton
He aha te whakaterenga (a) o te poraka?
Σ F = ma
wx = ma
30 = (5) he
ā = 30 / 5
a = 6 m/s 2
Ko te whakautu tika ko B.
2. Tirohia te pikitia! I te tīmatanga ka okioki tetahi poraka, kātahi ka tōia ki runga mā te kaha F e whakarara ana ki te papa whakarara. Ko te taumaha o te poraka he 8 kg, ko te tauwehenga o te waku µs = 0,5 me te θ = 45 o . Kia tika ai te neke o te poraka ki runga, me… te kaha F.
A. 40 N
B. 60 N
C. 60√2 N
D. 80 N
E. 80√2 N
Kōrero
E mōhiotia ana :
Tauwehenga waku pumau (µs ) = 0,5
Koki (θ) = 45 o
Te whakaterenga nā te kaha ā-papa (g) = 10 m/s 2
Taumaha o te poraka (m) = 8 kirokaramu
Taumaha o te poraka (w) = mg = (8 kg)(10 m/s 2 ) = 80 kg m/s 2 = 80 Newtons
Pātai : Te rahi o te kaha F kia neke ake ai te poraka
Whakautu :
Ka neke ake te poraka mēnā ko F ≥ w x + f s.
Te wāhanga o te kaha ā-papa e whakarara ana ki te papa whakarara :
w x = w hara θ = (80)(hara 45) = (80)(0,5√2) = 40√2
Te wāhanga o te kaha ā-papa e poutū ana ki te papa whakarara :
w y = w cos θ = (80)(cos 45) = (80)(0,5√2) = 40√2
Te kaha noa :
N = w y = 40√2
Te kaha waku pumau :
f s = µ s N = (0,5)(40√2) = 20√2
Te rahi o te kaha F kia neke ake ai te poraka :
F ≥ w x + f s
F ≥ 40√2 + 20√2
F ≥ 60√2 Newton
Ko te whakautu tika ko C.
3. Kei runga i tētahi papa whakarara te poraka, e 8 kg te taumaha, e whakaaturia ana i te pikitia e whai ake nei. Ko te kaha o waho iti rawa e hiahiatia ana hei ārai i te poraka kei paheke ki raro ko… (sin 37 o = 0,6, cos 37 o = 0,8, g = 10 ms -2 , µ k = 0,1)
A. 6,4 N
B. 4,6 N
C. 48,5 N
D. 54,4 N
E. 68,8 N
Kōrero
E mōhiotia ana :
Taumaha o te poraka (m) = 8 kg
Te whakaterenga nā te kaha ā-papa (g) = 10 m/s 2
Taumaha o te poraka (w) = mg = (8)(10) = 80 Newton
Sin 37 o = 0,6
Cos 37 o = 0,8
Tauwehenga o te waku nekeneke (µk ) = 0,1
N = w y = w cos 37 o = (80)(0,8) = 64 Ngā Newton
Pātai : Ko te kaha o waho iti rawa (F) e hiahiatia ana hei tautoko i te poraka kia kore ai e paheke ki raro.
Whakautu :
Kāore te poraka e paheke ki raro mēnā ko F = w x
Te wāhanga o te kaha ā-papa e whakarara ana ki te papa whakarara :
w x = w hara θ = (80)(hara 37) = (80)(0,6) = 48
f k = µ k N = (0,1)(64) = 6,4
Te kaha iti rawa F kia kore ai te poraka e paheke ki raro :
F + f k – w x = 0
F = w x – f k = 48 – 6,4 = 41,6 Ngā Newton
4. Ka tōia tētahi mea he 5,0 kg te taumaha ki runga i tētahi papa whakarara taratara mā te kaha o te 71 N (g = 10 m s -2 , sin 37 o = 0,6, cos 37 o = 0,8). Mena ko te tauwehenga waku i waenga i te mea me te papa he 0,4, ko te whakaterenga e pā ana ki te mea ko…
A. 0,5 ms-2
B. 2 ms -2
C. 2,5 ms -2
D. 3 ms -2
E. 5 ms -2
Kōrero
E mōhiotia ana :
Papatipu o te mea (m) = 5 kg
4. Ngā Pātai Whakamātautau Ā-Motu mō te Ahupūngao SMA 2012/2013 SA 67 Nama 5
Ka tōia tētahi mea 5,0 kg te taumaha e te taura ki runga i tētahi papa whakarara taratara mā te kaha o te 71 N (g = 10 m s -2 , sin 37 o = 0,6, cos 37 o = 0,8). Mena ko te tauwehenga waku i waenga i te mea me te papa he 0,4, ko te whakaterenga e pā ana ki te mea ko…
A. 0,5 ms -2
B. 2 ms -2
C. 2,5 ms -2
D. 3 ms -2
E. 5 ms -2
Kōrero
E mōhiotia ana :
Papatipu o te mea (m) = 5 kg
Te whakaterenga nā te kaha ā-papa (g) = 10 m/s 2
Taumaha o te taonga (w) = mg = (5)(10) = 50 Newton
Te Kaha F = 71 Newton
Sin 37 o = 0,6
Cos 37 o = 0,8
Tauwehenga o te waku = 0,4
Pātai : Te whakaterenga o te mea (a)
Whakautu :
Te Kaha Hua
Tuatahi, tatauhia te kaha hua e pā ana ki te mea.
Te wāhanga o te kaha ā-papa e whakarara ana ki te papa whakarara :
w x = w hara θ = (50)(hara 37) = (50)(0,6) = 30
Te wāhanga o te kaha ā-papa e poutū ana ki te papa whakarara :
w y = w cos θ = (50)(cos 37) = (50)(0,8) = 40
Kāhua noa :
N = w y = 40
Te kaha waku nekeneke :
f k = µ k N = (0,4)(40) = 16
Te kaha hua e pā ana ki tētahi papa whakarara:
∑ F = F – w x – f k = 71 – 30 – 16 = 25 Ngā Newton
Te whakaterenga o tētahi mea
Ka tatauhia te whakaterenga o tētahi mea mā te whakamahi i te tātai ture tuarua a Newton:
a = ∑F / m = 25 / 5 = 5 m/s 2
Ko te whakautu tika ko E.
5.
Tirohia te pikitia! I te tīmatanga ka okioki tetahi poraka, kātahi ka tōia ki runga me te kaha F e whakarara ana ki te papa piko. Ko te taumaha o te poraka he 8 kg, ko te tauwehenga o te waku he µ.s = 0,5 me θ = 45oKia taea ai e te poraka te neke ake, me rite te kaha F ki te….
A. 40 N
B. 60 N
C. 60√2 N
D. 80 N
E. 80√2 N
Kōrero
E mōhiotia ana :
Tauwehenga te waku pumau (µ)s) = 0,5
Koki (θ) = 45o
Te whakaterenga nā te kaha ā-papa (g) = 10 m/s2
Taumaha o te poraka (m) = 8 kirokaramu
Taumaha o te poraka (w) = mg = (8 kg)(10 m/s)2) = 80 kg m/s2 = 80 Niutona
I pātaihia : Te rahi o te kaha F kia neke ake ai te poraka
Whakautu :
Ka neke ake te poraka matau mēnā F ≥ wx + fs.
Te wāhanga o te kaha ā-papa e whakarara ana ki te papa whakarara :
wx = w hara θ = (80)(hara 45) = (80)(0,5√2) = 40√2
Te wāhanga o te kaha ā-papa e poutū ana ki te papa whakarara :
wy = w cos θ = (80)(cos 45) = (80)(0,5√2) = 40√2
Te kaha noa :
N = wy = 40√2
Te kaha waku pumau :
fs = µs N = (0,5)(40√2) = 20√2
Te rahi o te kaha F kia neke ake ai te poraka :
F ≥ wx + fs
F ≥ 40√2 + 20√2
F ≥ 60√2 Newton
Ko te whakautu tika ko C.
6.
Kei runga i tētahi papa whakarara te poraka, e 8 kg te taumaha, e whakaaturia ana i te pikitia i raro nei. Ko te kaha o waho iti rawa e hiahiatia ana hei ārai i te poraka kei paheke ki raro ko… (sin 37o = 0,6, cos 37o = 0,8, karamu = 10 ms-2, µk = 0,1)
A. 6,4 N
B. 4,6 N
C. 48,5 N
D. 54,4 N
E. 68,8 N
Kōrero
E mōhiotia ana :
Taumaha o te poraka (m) = 8 kg
Te whakaterenga nā te kaha ā-papa (g) = 10 m/s2
Taumaha o te poraka (w) = mg = (8)(10) = 80 Newton
Hara 37o = 0,6
Kohinga 37o = 0,8
Tauwehenga o te waku nekeneke (µ)k) = 0,1
I pātaihia : Te kaha o waho iti rawa (F) e pupuri ana i te poraka kia kore ai e paheke ki raro
Whakautu :
Kāore te poraka e paheke ki raro mēnā F = wx
Te wāhanga o te kaha ā-papa e whakarara ana ki te papa whakarara :
wx = w hara θ = (80)(hara 37) = (80)(0,6) = 48
fk = µk N = (0,1)(64) = 6,4
Te kaha iti rawa F kia kore ai te poraka e paheke ki raro :
F + fk - wx = 0
F = wx - fk = 48 – 6,4 = 41,6 Nītona
7.
Ka kumea tētahi mea he 5,0 kg te taumaha e te taura ki runga i tētahi papa whāiti taratara mā te kaha o te 71 N (g = 10 m s ).-2, hara 37o = 0,6, cos 37o = 0,8). Mena ko te tauwehenga o te waku i waenga i te mea me te papa he 0,4, ko te whakaterenga e pā ana ki te mea ko…
A. 0,5 ms-2
B. 2 ms-2
C. 2,5 ms-2
D. 3 ms-2
E. 5 ms-2
Kōrero
E mōhiotia ana :
Papatipu o te mea (m) = 5 kg
Te whakaterenga nā te kaha ā-papa (g) = 10 m/s2
Taumaha o te taonga (w) = mg = (5)(10) = 50 Newton
Te Kaha F = 71 Newton
Hara 37o = 0,6
Kohinga 37o = 0,8
Tauwehenga o te waku = 0,4
I pātaihia Te whakaterenga o te mea (a)
Whakautu :
Te Kaha Hua
Tuatahi, tatauhia te kaha hua e pā ana ki te mea.
Te wāhanga o te kaha ā-papa e whakarara ana ki te papa whakarara :
wx = w hara θ = (50)(hara 37) = (50)(0,6) = 30
Te wāhanga o te kaha ā-papa e poutū ana ki te papa whakarara :
wy = w cos θ = (50)(cos 37) = (50)(0,8) = 40
Te kaha noa :
N = wy = 40
Te kaha waku nekeneke :
fk = µk N = (0,4)(40) = 16
Te kaha hua e pā ana ki tētahi papa whakarara:
∑F = F – wx - fk = 71 – 30 – 16 = 25 Ngā Newton
Te whakaterenga o tētahi mea
Ka tatauhia te whakaterenga o tētahi mea mā te whakamahi i te tātai ture tuarua a Newton:
a = ∑F / m = 25 / 5 = 5 m/s2
Ko te whakautu tika ko E.
8. Tirohia te pikitia! I te tīmatanga ka okioki tetahi poraka, kātahi ka tōia ki runga mā te kaha F e whakarara ana ki te papa piko. Ko te taumaha o te poraka he 2 kg, ko te tauwehenga o te waku pateko = 0,3, ā, ko te koki = 45 o . Kia tika ai te neke o te poraka ki runga, ko te kaha F me… g = 10 m/s 2
Kōrero
E mōhiotia ana:
m = 2 kg, karamu = 10 m/s2, = 45o, μs = 0,3
Pātai: Kia tika ai te neke o te poraka ki runga, e hia te rahi o te kaha F?
Whakautu:
Ngā Mōhiotanga: F = te kaha kume, w = te kaha ā-papa, wx = te wāhanga o te taumaha o te poraka e whakarara ana ki te mata o te papa whakarara, wy = te wāhanga o te taumaha o te poraka e poutū ana ki te mata o te papa whakarara, N = te kaha noa, fs = te kaha waku pumau.
I roto i te pātai, e mōhiotia ana te tauwehenga o te waku pateko, ko te tikanga he taratara te mata o te papa piko, nō reira he kaha waku e aukati ana i te nekehanga o te poraka.
Kia taea ai e te poraka te neke ake, me ōrite te kaha F ki te w.x +fsKa neke ake te mea ina nui ake a F i a wx +fs.
w = mg = (2)(10) = 20 Ngā Niutona
wx = w sin 45o = (20)(½ √2) = 10√2 Ngā Newton
wy = w cos 45o = (20)(½√2) = 10√2 Ngā Newton
N = wy = 10√2
fs = μs N = (0,3)(10√2) = 3√2 Ngā Newton
Kia neke ake ai te poraka:
F = wx +fs = 10√2 + 3√2= 13√2 Ngā Newton
Ko te whakautu tika ko C.
9. Kei runga i tētahi papa whakarara te taumaha o tētahi mea, e 2 kg te taumaha, e whakaaturia ana i te pikitia i raro nei. Mēnā ko te tauwehenga o te waku pūmau i waenga i te poraka me te papa whakarara he 0,2√3, ā, ko te g = 10 ms –2 , ko te kaha hua e neke ai te mea ko…

Kōrero
E mōhiotia ana:
m = 2 kg, karamu = 10 m/s2, = 30o, μs = 0,2√3
I pātaihia: Ko te kaha hua e neke ai tētahi mea?
Whakautu:
Ka ārai tonu te waku i te nekehanga o tētahi mea, nō reira ka whakaaturia te ahunga o te kaha waku he rerekē ki te ahunga o te nekehanga o te mea. E whakaarohia ana kei te neke te mea ki raro, nō reira ka whakaaturia te kaha waku ki runga. E whakaarohia ana kei te neke te mea ki raro nā te mea kāore he kaha e kukume ana i a ia ki runga.
w = mg = (2)(10) = 20 Ngā Niutona
wx = w sin 30o = (20)( ½ ) = 10 Newton
wy = w cos 30o = (20)( ½ √3) = 10√3 Ngā Newton
N = wy = 10√3 Nūtene
fs = μs N = (0,2√3)(10√3) = (2)(3) = 6 Ngā Niutoni
Ko te kaha hua e neke ai tētahi mea ko:
F = wx - fs = 10 – 6 = 4 Nītona
wx nui atu i te fs nō reira ka neke te mea ki raro, i te ahunga o wx.
Ko te whakautu tika ko A.
Pūtake pātai:
Ngā Pātai Ahupūngao Whakamātautau ā-Motu mō te Kura Tuarua/Kura Tuarua Mahi-ā-ringa