Malamulo a Newton oyendetsera zinthu - mavuto ndi mayankho

Malamulo a Newton oyendetsera zinthu - mavuto ndi mayankho

Lamulo loyamba la Newton la kayendedwe

1. Ngati palibe mphamvu yogwiritsira ntchito mphamvu pa chinthu, ndiye kuti:

(1) chinthucho sichikufulumizitsidwa

(2) chinthu chomwe chili pamalo opumulira

(3) kusintha kwa liwiro la chinthu = 0

(4) chinthucho sichingayende pa liwiro losasintha

Ndi chiganizo chiti chomwe chili cholondola?

Anakonza

Chiganizo cholondola:

(1) Chinthucho sichikufulumizitsidwa

Mphamvu ya neti imayambitsa kufulumira kwa chinthu. Choncho ngati palibe mphamvu ya neti ndiye kuti zinthu sizimafulumizitsidwa.

(2) Chinthu chili pamalo opumulira

Lamulo loyamba la Newton loyendetsa zinthu limati ngati palibe mphamvu yogwira ntchito pa chinthu, ndiye kuti chinthucho chimakhala chokhazikika nthawi zonse kapena chinthucho chimayenda nthawi zonse pa liwiro losasintha.

(3) Kusintha kwa liwiro la chinthu = 0

Kusintha kwa liwiro = kufulumizitsa. Kusasintha kwa liwiro kumatanthauza kuti palibe kufulumizitsa. Ngati palibe kufulumizitsa, palibe mphamvu yogwira ntchito pa chinthu.

Chinthucho chili mu elevator

2. Kulemera kwa munthu amene ali mu elevator pamene akupumula = 500 N. Kuthamanga chifukwa cha mphamvu yokoka ndi 10 m/s ^2. Pamene elevator ikuthamanga, mphamvu ya kukakamira ndi 750 N. Kodi kuthamanga kwa elevator ndi chiyani?

Zodziwika:

Kulemera kwa munthu (w) = 500 Newton = 500 kg ms ^–2 (kunyamula munthu ali pamalo opumulira)

Kuthamanga kwa mphamvu yokoka (g) = 10 ms ^–2

Kulemera kwa munthu (m) = 500 / 10 = 50 kg

Mphamvu ya kukakamira (T) = 750 N (kukweza kwachangu)

Unyinji wa elevator wanyalanyazidwa.

Kufunidwa: Kufulumizitsa ma elevator

Yankho:

Chikepe chili pamalo opumulira, palibe kuthamanga (a = 0). Zochita zamphamvu mmwamba zili ndi chizindikiro chowonjezera ndipo zochita zamphamvu pansi zili ndi chizindikiro chochotsera.

ΣF = ma

T – w = 0

T = w

T = 500 Newtons

Ngati elevator yathamanga pansi ndiye kuti mphamvu ya kukakamira imakhala yochepa kwambiri kuposa 500 N. Apo ayi, ngati elevator yathamanga mmwamba ndiye kuti mphamvu ya kukakamira imakhala yayikulu kuposa 500 N.

Mphamvu ya kukakamira = 750 N chifukwa elevator imathamanga mmwamba. Mphamvu ya kukakamira mmwamba imakhala ndi chizindikiro chowonjezera ndipo mphamvu ya kukakamira pansi imakhala ndi chizindikiro chochotsera.

T – w = ma

750 – 500 = 50 a

250 = 50 a

a = 250 / 50

a = 5.0 ms ^–2

3. Munthu wolemera makilogalamu 60 mu elevator anathamanga mofulumira pansi pa 3 m/s ^2. Ngati kuthamanga chifukwa cha mphamvu yokoka ndi 10 m/s ² , kodi mphamvu yachibadwa yomwe pansi pa elevator imaperekedwa ndi yotani pa munthuyo?

Zodziwika:

Kulemera (m) = 60 kg

Kuthamanga kwa munthu ndi elevator (a) = 3 m/s ²

Kuthamanga chifukwa cha mphamvu yokoka (g) = 10 m/s ²

Kulemera (w) = mg = (60)(10) = 600 Newtons

Kufunidwa: Mphamvu yachibadwa (N)

Yankho:

Pali mphamvu ziwiri zomwe zimachitika pa munthu amene ali mu elevator, zomwe ndi kulemera (w) kwa munthuyo ndi mphamvu yachibadwa (N) yomwe pansi pake pa munthuyo. Pali mphamvu zitatu za vekitala, zomwe ndi kulemera (w), mphamvu yachibadwa (N) ndi kufulumira kwa elevator, komwe kulemera kumachita pansi, mphamvu yachibadwa imachita mmwamba, kufulumira kwa elevator kumakhala pansi. Kuchuluka kwa vekitala komwe kumachita pansi kuli ndi chizindikiro chowonjezera ndipo kuchuluka kwa vekitala komwe kumachita mmwamba kuli ndi chizindikiro chochotsera.

∑F = ma

w – N = (60)(3)

600 – N = 180

N = 600 - 180

N = 420 Newton

4. Chinthu cholemera makilogalamu 40 chomwe chili mu elevator chinakwera mofulumira kupita mmwamba. Ngati pansi pa elevator pali 520 N pa chinthucho ndipo kuthamanga chifukwa cha mphamvu yokoka ndi 10 m/s ^2. Kodi kuthamanga kwa elevator ndi chiyani?

Zodziwika:

Kulemera (m) = 40 kg

Mphamvu yachibadwa (N) = 520 N

Kuthamanga chifukwa cha mphamvu yokoka (g) = 10 m/s ²

kulemera (w) = mg = (40)(10) = 400 N

Kufunidwa: Kufulumizitsa lifti

Yankho:

∑F = ma

400 – 520 = (40)(a)

-120 = (40)(a)

a = -120/40

a = -3 m/s ²

Kuthamanga kwa elevator ndi 3 m/s ^2. Chizindikiro chochotsera chimasonyeza kuti elevator ikuyenda mmwamba.

5. Chinthu cholemera makilogalamu 60 mu elevator chinatsika mofulumira pa 3 m/s ^2. Kodi mphamvu zomwe zinthu zomwe zili pansi pa elevator zimagwiritsira ntchito ndi ziti?

Zodziwika:

Kulemera (m) = 60 kg

Kulemera (w) = mg = (60 kg)(10 m/s ² ) = 600 kg m/s ² = 600 Newtons

Kuthamanga kwa elevator (a) = 3 m/s ² , pansi

Kufunidwa: Mphamvu yogwiritsidwa ntchito ndi chinthu chomwe chili pansi pa elevator.

Yankho:

Chikepecho chinatsika mofulumira pa 3 m/s . Zochita zamphamvu pansi zili ndi chizindikiro cha plus ndipo zochita zamphamvu mmwamba zili ndi chizindikiro cha mid-.

w – N = ma

N = w – ma

N = 600 – (60)(3)

N = 600 - 180

N = 420 Newton

Mphamvu yogwiritsidwa ntchito ndi chinthu chomwe chili pansi pa elevator = 420 N.

6. Mabuloko awiri amalumikizidwa ndi chingwe chomwe chikuyenda pamwamba pa pulley. Musanyalanyaze kulemera kwa chingwe ndi pulley ndi kukangana kulikonse mu pulley. Kulemera kwa block A ndi 6 kg ndipo kulemera kwa block B ndi 2 kg. Kuthamanga chifukwa cha mphamvu yokoka ndi 10 m/s ^2. Kodi mphamvu ya kukakamira ndi chiyani?

Zodziwika:

m _A = 6 kg, m _B = 2 kg, g = 10 m/s ²

w _A = m _A g = (6 kg)(10 m/s ² ) = 60 kg m/s ²

w _B = m _B g = (2 kg)(10 m/s ² ) = 20 kg m/s ²

Akufuna: mphamvu ya kukangana (T)?

Yankho:

w _A > w _B kotero kuti m _A isunthire pansi , m _B isunthire mmwamba.

Lamulo lachiwiri la Newton:

Σ F = ma

w _A – w _B = (m _A + m _B ) a

60 – 20 = (6 + 2) a

40 = (8) a

a = 40 / 8 = 5 m/s ²

Mphamvu ya kukangana:

m _A ikutsika pansi:

w _A – T _A = m _A a

60 – T _A = (6)(5)

60 – TA ₌ 30

TA = 60 - ₃₀

T ₂ = 30 Newton

m _B ikukwera mmwamba:

T _B – w _B = m _B a

T _B – 20 = (2)(5)

T _B – 20 = 10

T _B = 10 + 20

T ₁ = 30 Newton

Mphamvu ya kukangana (T) = 30 Newtons.

7. Kulemera kwa chinthu A = 5 kg, kuthamanga chifukwa cha mphamvu yokoka (g) = 10 ms ^-2 . Chinthu A chimatsika pansi pa 2.5 ms ^-2 . Kodi kulemera kwa B ndi kotani?

Zodziwika:

Kulemera A (m _A ) = 5 kg

Kuthamanga chifukwa cha mphamvu yokoka (g) = 10 m/s ²

Kuthamanga kwa chinthu A (a) = 2.5 m/s ²

Kulemera A (w _A ) = (m _A )(g) = (5)(10) = 50 Newtons

Kufunidwa: Unyinji wa chinthu B (m _B )

Yankho:

Block A imatsika pansi kotero kulemera kwa chinthu A (w _A ) kumakhala kwakukulu kuposa kulemera kwa chinthu B (w _B ).

Gwiritsani ntchito lamulo lachiwiri la Newton:

Σ F = ma

w _A – w _B = (m _A + m _B ) a

50 – (m _B )(10) = (5 + m _B ) (2.5)

50 – 10 m _B = 12.5 + 2.5 m _B

50 – 12.5 = 2.5 m _B + 10 m _B

37.5 = 12.5 m _B

m _B = 3 kg

8. Kuthamanga chifukwa cha mphamvu yokoka ndi 10 m/s ^2. Kodi mphamvu ya kukakamira ndi chiyani?

Zodziwika:

Kulemera kwa chinthu 1 (m₁) = 2 kg

Kulemera kwa chinthu 2 (m2 ₎ = 3 kg

Kuthamanga chifukwa cha mphamvu yokoka (g) = 10 m/s ²

Kulemera 1 (w ₁ ) = (m ₁ )(g) = (2 kg)(10 m/s ² ) = 20 kg m/s ²

Kulemera 2 (w ₂ ) = (m ₂ )(g) = (3 kg)(10 m/s ² ) = 30 kg m/s ²

Akufuna: mphamvu ya kukangana (T)

Yankho:

w ₂ > w ₁ kotero kuti m ₂ isunthire pansi ndipo m ₁ isunthire mmwamba.

Lamulo lachiwiri la Newton la kayendedwe:

Σ F = ma

w ₂ – w ₁ = (m ₁ + m ₂ ) a

30 – 20 = (2 + 3) a

10 = (5) a

a = 10 / 5 = 2 m/s ².

Mphamvu ya kukangana?

m2 _imapita pansi

w ₂ – T ₂ = m ₂ a

30 – T ₂ = (3)(2)

30 – T ₂ = 6

T ₂ = 30 – 6

T ₂ = 24 Newton

m ₁ imapita mmwamba

T ₁ – w ₁ = m ₁ a

T ₁ – 20 = (2)(2)

T ₁ – 20 = 4

T ₁ = 20 + 4

T ₁ = 24 Newton

Mphamvu ya kukangana (T) = 24 Newtons.

1. funso: N’chifukwa chiyani lamulo loyamba la Newton la kuyenda limagogomezera kufunika kwa mphamvu zakunja pakusintha momwe chinthu chikuyendera? Yankho: Lamulo loyamba la Newton loyendetsa, lomwe nthawi zambiri limatchedwa lamulo la inertia, limati chinthu chimakhalabe chilili kapena chimayenda mofanana mumzere wowongoka pokhapokha ngati mphamvu yakunja ichitapo kanthu. Lamuloli likuwonetsa kuti ndi mphamvu zakunja, osati makhalidwe amkati mwa chinthucho, zomwe zingasinthe momwe chikuyendera.
2. funso: Kodi lamulo lachiwiri la Newton limagwirizana bwanji ndi mphamvu, kulemera, ndi kufulumira? Yankho: Lamulo lachiwiri la Newton la kuyenda limati mphamvu yomwe imagwira ntchito pa chinthu ndi yofanana ndi kulemera kwa chinthucho kuchulukitsidwa ndi kuthamanga kwake ($F=ma$Izi zimakhazikitsa kufanana kwachindunji pakati pa mphamvu ndi kuthamanga kwa mphamvu ndi kufanana kosiyana pakati pa kulemera ndi kuthamanga kwa mphamvu, poganizira mphamvu yosasinthika.
3. funso: Bwanji simukumva Dziko Lapansi likuyenda ngakhale kuti likuyenda nthawi zonse? Yankho: Ichi ndi chitsanzo cha lamulo loyamba la Newton. Ife, pamodzi ndi Dziko Lapansi ndi chilichonse chomwe chili mmenemo, tikuyenda limodzi mofanana. Popanda mphamvu yakunja yosinthira kayendedwe kameneka, palibe kumverera kwa kuthamanga kapena kusintha, zomwe zimapangitsa kuti ziwoneke ngati tili chete.
4. funso: Kodi lamulo lachitatu la Newton limafotokoza bwanji momwe roketi imagwirira ntchito mumlengalenga? Yankho: Lamulo lachitatu la Newton limati pa chilichonse chomwe chimachitika, pali kuchitapo kanthu kofanana komanso kosiyana. Roketi yomwe ili mumlengalenga imadziyendetsa yokha potulutsa mpweya wotulutsa utsi kumbuyo. Kuchitapo kanthu ndi mpweya womwe ukubwerera m'mbuyo, ndipo kuchitapo kanthu ndi roketi yomwe ikupita patsogolo.
5. funso: N’chifukwa chiyani mumayenda patsogolo m’galimoto ikaima mwadzidzidzi? Yankho: Malinga ndi lamulo loyamba la Newton, thupi lanu limapitiriza kuyenda (kutsogolo) galimoto ikaima. Pokhapokha ngati mphamvu (monga lamba wachitetezo) ikugwirani ntchito, mudzapitiriza kuyenda chifukwa cha kulephera kugwira ntchito.
6. funso: Ngati nthenga ndi nyundo zagwetsedwa mu vacuum, kodi malamulo a Newton anganene chiyani za kayendedwe kawo? Yankho: Mu vacuum, palibe kukana kwa mpweya. Kutengera malamulo oyamba ndi achiwiri a Newton, nthenga ndi nyundo ziyenera kugwa mofanana ndikugunda pansi nthawi imodzi chifukwa mphamvu yokhayo yomwe imagwira ntchito pa izo ndi mphamvu yokoka.
7. funso: Kodi chikwama cha mpweya chimachepetsa bwanji mwayi wovulala pa ngozi ya galimoto? Yankho: Lamulo loyamba la Newton limasonyeza kuti chinthu chomwe chikuyenda chimakhalabe choyenda. Pakagwa ngozi, munthu amapitiliza kuyenda patsogolo. Chikwama cha mpweya chimapereka malo otetezedwa omwe amawonjezera nthawi yochepetsera liwiro, motero amachepetsa mphamvu yomwe munthuyo amakumana nayo malinga ndi $F=ma$.
8. funso: N’chifukwa chiyani n’kosavuta kukankhira ngolo yogulira zinthu yopanda kanthu kuposa yodzaza ndi zinthu? Yankho: Lamulo lachiwiri la Newton ($F=ma$) akusonyeza kuti pa mphamvu yofanana yomwe imagwiritsidwa ntchito, chinthu chokhala ndi kulemera kochepa (ngolo yopanda kanthu) chidzakhala ndi liwiro lalikulu kuposa chinthu chokhala ndi kulemera kwakukulu (ngolo yodzaza).
9. funso: N’chifukwa chiyani munthu wosambira amakankhira madzi kumbuyo kuti apite patsogolo? Yankho: Ichi ndi chitsanzo cha lamulo lachitatu la Newton. Wosambira akakankhira madzi kumbuyo (kuchitapo kanthu), pamakhala kuchitapo kanthu kofanana komanso kosiyana komwe kumamupangitsa wosambirayo kupita patsogolo.
10. funso: Kodi kukangana kumagwirizana bwanji ndi lamulo loyamba la Newton? Yankho: Kukangana ndi mphamvu yakunja yomwe ingathe kugwira ntchito pa zinthu kuti zichepetse liwiro kapena kuletsa kuyenda kwawo. Popanda kukangana (kapena mphamvu ina iliyonse yakunja), chinthu chingapitirize kuyenda kwake kosatha monga momwe lamulo loyamba la Newton linanenera.