Ka'idar Makamashin Aiki-Kinetic
Idan ƙarfin yanar gizo ya yi aiki a kan wani abu, abu yana fuskantar hanzari (abin yana fuskantar ƙaura). Lokacin da abu ya fuskanci hanzari, saurin abu yana canzawa. A wata ma'anar, aikin da ƙarfin yanar gizo ya yi yana da alaƙa da saurin farko da na ƙarshe na abu.
Aikin da ake yi akan wani abu ta hanyar amfani da ƙarfin net mai ɗorewa shine:
W net = ΣF s
Dokar Newton ta biyu ta bayyana cewa idan akwai ƙarfin da ke aiki a kan wani abu, abin yana fuskantar hanzari.
W net = (ma) s
Idan ƙarfin da ke cikin net ɗin ya kasance mai daidaito, saurin da abin ya samu shima yana da daidaito. Saboda haka, za mu iya maye gurbin daidaitaccen motsi na layi mara daidaito da saurin gudu (a) da ƙaura (s).
Haɗa lissafin motsi mara daidaito a cikin lissafin aiki:
Bayani: EK t = kuzarin motsi na ƙarshe, EK o = kuzarin motsi na farko, m = taro, v t = saurin ƙarshe, v o = saurin farko
Wannan lissafi ya ƙunshi ka'idar makamashin aiki-kinetic. Ka'idar makamashin aiki-kinetic ta sanar da mu cewa aikin yanar gizo ko aikin da ƙarfin yanar gizo ke yi akan wani abu daidai yake da canjin kuzarin motsi na abu. Hakanan yana sanar da mu cewa kuzarin motsi na abu daidai yake da aikin yanar gizo da ake buƙata don hanzarta abu daga yanayin da ba ya tsayawa zuwa motsi a wani saurin da aka bayar, da kuma akasin haka.
Misali tambaya ta 5: Ka'idar makamashin aiki-kinetic
Mota mai nauyin kilogiram 1000 tana motsawa daga yanayin da ba ta tsayawa. Nan take, saurin zai ƙaru zuwa mita 10/s. Nawa ne aikin da injinan motar ke yi?
Magani:
An sani: m = 1000 kg, v o = saurin farko = 0 m/s (da farko, motar tana hutawa), v t = gudun ƙarshe = 10 m/s
Ana so: Cibiyar sadarwa
W net = 1⁄2 m (v t 2 – v o 2 )
W net = 1⁄2 (1000)(10 2 – 0 2 ) = (500)(100 – 0) = (500)(100) = 50,000 Joules
1. Menene ƙa'idar Makamashin Aiki-Kinetic? ƙa'idar Makamashin Aiki-Kinetic ta bayyana cewa aikin da aka yi akan wani abu daidai yake da canjin kuzarin motsi. A lissafi, , inda shine kuzarin motsi na ƙarshe banda kuzarin motsi na farko.
2. Ta yaya aikin yake da alaƙa da canjin saurin abu? Aikin da aka yi akan abu zai iya canza saurinsa. Musamman ma, aikin da aka yi akan abu daidai yake da canjin kuzarin motsi, kuma kuzarin motsi yana da alaƙa da murabba'in gudu. Don haka, idan an yi aikin cibiyar sadarwa mai kyau akan abu, saurinsa (da kuma kuzarin motsi) yana ƙaruwa.
3. Me ke faruwa da kuzarin motsi na abu idan aka yi aiki mara kyau a kansa? Idan aka yi aiki mara kyau a kan abu, kuzarin motsi nasa yana raguwa. Wannan na iya haifar da raguwar abu.
4. Ta yaya ƙa'idar Makamashi ta Work-Kinetic ta shafi dokar Newton ta biyu? Dokar Newton ta biyu ta bayyana yadda ƙarfi ke shafar motsin abu, yayin da ƙa'idar Makamashi ta Work-Kinetic ta danganta aikin da wannan ƙarfin ya yi da canjin kuzarin motsi. Duk waɗannan ra'ayoyin suna da alaƙa ta hanyar ra'ayin cewa ƙarfi na iya canza yanayin motsi da kuzarin abu.
5. Shin kuzarin motsi na abu zai iya zama mara kyau? A'a, kuzarin motsi koyaushe ba mara kyau bane. Ana bayar da shi ta hanyar dabarar , inda m shine taro kuma v shine gudu. Tunda duka taro da murabba'in gudu suna da kyau, kuzarin motsi shima tabbatacce ne ko sifili.
6. Ta yaya ƙa'idar Makamashin Aiki-Kinetic ta shafi abu da ke tafiya a cikin hanyar da'ira? Ga abu da ke tafiya a cikin hanyar da'ira a cikin saurin da'ira, kuzarin motsi nasa ya kasance daidai tunda saurinsa ba ya canzawa. Duk da haka, alkiblar saurinsa tana canzawa akai-akai. Idan ƙarfin centripetal kawai (kamar tashin hankali ko ƙarfin nauyi) ke aiki akan abu, aikin da waɗannan ƙarfin ke yi ba sifili bane yayin da suke aiki daidai da alkiblar motsi. Don haka, babu aikin yanar gizo da ake yi, kuma babu canji a cikin kuzarin motsi.
7. Idan babu ƙarfin waje, ta yaya kuzarin motsi na abu yake canzawa? Idan babu ƙarfin waje, babu wani aiki da ake yi akan abu, wanda ke nufin kuzarin motsi nasa yana nan daram. Wannan alama ce ta kiyaye makamashi.
8. Me ake nufi idan aikin yanar gizo da aka yi akan abu sifili ne? Idan aikin yanar gizo da aka yi akan abu sifili ne, yana nufin kuzarin motsin abu bai canza ba. Abu zai iya ci gaba da motsi, amma saurinsa ya kasance iri ɗaya.
9. Shin abu zai iya samun kuzarin motsi koda kuwa ba a yi wani aiki a kansa ba? Haka ne, abu zai iya samun kuzarin motsi ba tare da an yi wani aiki a kansa ba a cikin wani lokaci da aka ƙayyade. Misali, abu da ya riga ya fara motsi a sararin samaniya (daga jikin nauyi) zai riƙe kuzarin motsi kuma ya ci gaba da tafiya a cikin sauri mai ɗorewa, koda kuwa babu wani ƙarfin waje da ke aiki a kansa.
10. Ta yaya aikin da sojojin da ba na masu ra'ayin mazan jiya ke yi yake shafar kuzarin motsi na wani abu? Aikin da sojojin da ba na masu ra'ayin mazan jiya ke yi na iya ƙara ko rage kuzarin motsi na wani abu, ya danganta da alkibla da girman ƙarfin da ya danganta da motsin abu. Misali, gogayya, ƙarfin da ba na masu ra'ayin mazan jiya ba, yawanci yana yin aiki mara kyau, ta haka yana rage kuzarin motsi na wani abu.
