Lamulo lachiwiri la Newton pa kayendedwe ka kuzungulira

Nkhani yokhudza lamulo lachiwiri la Newton lokhudza kuyenda kozungulira

4.1 Ubale pakati pa mphindi ya mphamvu, mphindi ya inertia, ndi kuthamanga kwa angular

Ngati pali mphamvu yochokera (ΣF) yomwe ikugwira ntchito pa chinthu chokhala ndi kulemera (m) ndiye kuti chinthucho chimayenda molunjika ndi kuthamanga kwina (a). Ubale pakati pa mphamvu yochokera, kulemera, ndi kuthamanga ukufotokozedwa ndi equation:

Σ F = ma

Iyi ndi njira yofanana ndi lamulo lachiwiri la Newton .

Kuchuluka kwa kayendedwe kozungulira komwe kuli kofanana ndi mphamvu yochokera (ΣF) mu kayendedwe kolunjika ndi mphindi yochokera ya mphamvu (Στ). Kuchuluka kwa kayendedwe kozungulira komwe kuli kofanana ndi kulemera (m) mu kayendedwe kolunjika ndi mphindi za inertia (I). Kuchuluka kwa kayendedwe kozungulira komwe kuli kofanana ndi kuthamanga (a) mu kayendedwe kolunjika ndi kuthamanga kwa angular (α).

Ngati pali mphamvu yochokera ku nthawi (Στ) yomwe ikugwira ntchito pa chinthu chomwe chili ndi nthawi inayake ya inertia (I) ndiye kuti chinthucho chimazungulira ndi angular acceleration (α). Ubale pakati pa mphamvu yochokera ku nthawi, nthawi ya inertia, ndi angular acceleration umafotokozedwa kudzera mu equation:

Στ = I α

Chilinganizo ichi ndi fanizo lozungulira la lamulo lachiwiri la Newton.

4.2 Zitsanzo za mavuto a lamulo lachiwiri la Newton pankhani yoyenda mozungulira

Chitsanzo cha vuto 1.

Pulley yolimba yokhala ndi kulemera kwa 1 kg ndi utali wa 10 cm, m'mphepete mwake, chingwe chokulungidwa, mbali imodzi ya chingwe chopachikidwa ndi katundu wa 1 kg. Ganizirani kuti chingwecho ndi chopanda kulemera. Dziwani kukula kwa kuthamanga kwa katunduyo pamene kugwa kwaulere kutsika. (g = 10 m/s²)

yankho;

Zodziwika:

F = w = mg = (1 kg)(10 m/s ² ) = 10 N

r = 0.1 m

Kufunidwa: Kufulumizitsa katundu

yankho;

Choyamba, werengerani mphindi ya inertia ndi mphindi ya mphamvu.

Nthawi ya inertia ya pulley yolimba:

I = 1⁄2 mr ² = 1⁄2 (1 kg)(0.1 m) ²

I = (0.5 kg)(0.01 m ² ) = 0.005 kg m ²

Nthawi ya mphamvu:

τ = F l = (10 N)(0.1 m) = 1 N m

Kuthamanga kwa angular:

Kufulumizitsa katundu:

a = r α = (0.1) (200) = 20 m/s ²

Chitsanzo cha vuto 2.

Pulley yolimba yokhala ndi kulemera kwa 2M ndi utali wa R, m'mphepete mwake, inakulunga chingwe, mbali imodzi ya chingwecho inapachikidwa ndi katundu wokhala ndi kulemera kwa m. Katunduyo akachotsedwa, pulley imazungulira ndi kuthamanga kwa angular. Ngati pulley yalumikizidwa ku chinthu chokhala ndi kulemera kwa M, kotero kuti pulley imazungulira ndi kuthamanga kwa angular komweko, dziwani kulemera kwa katunduyo. (I pulley = 1⁄2 MR ² ).

yankho;

Zodziwika:

Kulemera kwa pulley yolimba: 2M

Utali wozungulira wa pulley yolimba: R

Kulemera kwa katundu: m

Kufunidwa: Kulemera kwa katundu

yankho;

Werengerani nthawi ya inertia ya pulley yolimba, musanayambe komanso mutalumikiza zinthu ndi kulemera kwa M:

Nthawi ya kulephera 1: I = 1⁄2 mr ² = 1⁄2

(2M)(R) ² = MR ²

Nthawi ya kulephera 2: I = 1⁄2 mr ² = 1⁄2

(2M + M)(R) ² = 1⁄2 (3M)(R) ² = 1.5 MR ²

Mphindi ya mphamvu yomwe imachokera ku katundu pa pulley:

τ = F l = (m)(g)(R)

Kuthamanga kwa angular kwa pulley ndi chimodzimodzi, zonse zisanayambe komanso zitatha kulumikiza zinthu ndi kulemera kwa M.

Kulemera kwa katundu = 1.5 kuwirikiza kulemera kwa katundu woyambirira.