Fomula ya Bizinesi
Mu fizikisi, lingaliro la ntchito ndi lofunikira kwambiri, pofotokoza kusamutsa mphamvu komwe kumachitika pamene mphamvu imapangitsa chinthu kuyenda. Ntchito imagwira ntchito yofunika kwambiri pazochitika zosiyanasiyana zachilengedwe ndi ntchito zaukadaulo. Nkhaniyi ifotokoza mwatsatanetsatane njira yogwirira ntchito, zitsanzo, momwe imagwiritsidwira ntchito tsiku ndi tsiku, komanso ubale wake ndi mphamvu.
Tanthauzo la Bizinesi
Ntchito ndi kuchuluka kwa scalar komwe kumapangidwa pamene mphamvu yogwiritsidwa ntchito pa chinthu imapangitsa kuti chiyende. Ntchitoyi imachitika ndi mphamvu yomwe imayambitsa kusamuka kofanana ndi komwe mphamvuyo ikupita. Mu mayunitsi a SI, ntchito imayesedwa mu ma joules (J), pomwe joules imodzi ndi yofanana ndi mita imodzi ya newton (N·m).
Fomula yoyambira yowerengera ntchito (\(W \)) ndi iyi:
\[ W = F \cdot d \cdot \cos(\theta) \]
Kumene:
– \( W \) ndi ntchito,
– \( F \) ndi kukula kwa mphamvu yomwe imagwira ntchito pa chinthucho,
– \( d \) ndi kusamuka kwa chinthucho,
– \( \theta \) ndi ngodya pakati pa mbali ya mphamvu ndi mbali ya kusuntha.
Khama Lokhazikika
Pa mphamvu yosalekeza yomwe imagwira ntchito molingana ndi njira yosunthira (\( \theta = 0 \) kotero kuti \( \cos(0) = 1 \)), fomula yogwirira ntchitoyo ndi yosavuta:
\[ W = F \cdot d \]
Mwachitsanzo, ngati bokosi likankhidwa ndi mphamvu yosalekeza ya ma newton 10 pa mamita 5, ntchito yomwe yachitika ndi iyi:
\[ W = 10 \, \malemba{N} \nthawi 5 \, \malemba{m} = 50 \, \malemba{J} \]
Kotero, ntchito yomwe yachitika ndi ma joules 50.
Bizinesi Yosintha Kalembedwe
Ngati mphamvu yogwira ntchito pa chinthu isintha panjira yosuntha, ntchitoyo imawerengedwa pogwiritsa ntchito integral:
\[ W = \int_{x_1}^{x_2} F(x) \, dx \]
Integral iyi ikufotokoza ntchito yomwe yachitika ndi mphamvu zosiyanasiyana pamalo aliwonse osunthika kuchokera ku (x_1 \) kupita ku (x_2 \).
Chitsanzo cha Kuwerengera Ntchito ndi Mphamvu Yosintha
Tiyerekeze kuti mphamvu yogwira ntchito pa chinthu imasiyana ndi \( F(x) = 2x \) ndipo chinthucho chimayenda kuchokera ku \( x = 0 \) kupita ku \( x = 3 \) mamita. Ntchito yochitidwa ikhoza kuwerengedwa motere:
\[ W = \int_{0}^{3} 2x \, dx \]
\[ W = 2 \int_{0}^{3} x \, dx \]
\[ W = 2 \kumanzere[ \frac{x^2}{2} \kumanja]_{0}^{3} \]
\[ W = \kumanzere[ x^2 \kumanja]_{0}^{3} \]
\[ W = 3^2 – 0^2 \]
\[ W = 9 \, \lemba{J} \]
Kotero, ntchito yomwe yachitika ndi ma joules 9.
Khama Loipa
Ntchito ikhoza kukhala yoipa ngati mphamvu ikugwira ntchito mosiyana ndi kusuntha kwa galimoto. Mwachitsanzo, ngati titagwetsa galimoto yoyenda, mphamvu yokangana pakati pa matayala ndi msewu imagwira ntchito yoipa chifukwa mphamvu yokangana imatsutsana ndi kayendetsedwe ka galimotoyo.
Khama ndi Mphamvu
Ntchito imagwirizana kwambiri ndi mphamvu. Mfundo ya ntchito ndi mphamvu imati ntchito yochitidwa ndi mphamvu zonse zomwe zimagwira ntchito pa chinthu ndi yofanana ndi kusintha kwa mphamvu ya kayendedwe ka chinthucho. Mwa masamu:
\[ W = \Delta KE \]
\[ W = \frac{1}{2} m v_f^2 – \frac{1}{2} m v_i^2 \]
Kumene:
– \( \Delta KE \) ndi kusintha kwa mphamvu ya kinetic,
– \( m \) ndi kulemera kwa chinthucho,
– \( v_f \) ndi liwiro lomaliza la chinthucho,
– \( v_i \) ndi liwiro loyambirira la chinthucho.
Chitsanzo cha Kuwerengera Ntchito ndi Mphamvu ya Kinetic
Tiyerekeze kuti galimoto yolemera makilogalamu 1000 ikuyamba kuyenda pa liwiro la 10 m/s. Pambuyo pokumana ndi mphamvu yoletsa kutsekeka, galimotoyo imayima (liwiro lomaliza = 0 m/s). Ntchito yomwe gulu loletsa kutsekeka limachita ndi iyi:
\[ \Delta KE = \frac{1}{2} m v_f^2 – \frac{1}{2} m v_i^2 \]
\[ \Delta KE = \frac{1}{2} \times 1000 \, \text{kg} \times (0 \, \text{m/s})^2 – \frac{1}{2} \times 1000 \, \text{kg} \times (10 \, \text{m/s})^2 \]
\[ \Delta KE = 0 - 5000 \, \ zolemba{J} \]
\[ \Delta KE = -5000 \, \lemba{J} \]
Kotero, ntchito yomwe yachitika ndi mphamvu yoletsa mabuleki ndi -5000 joules, zomwe zikusonyeza kuti mphamvu ya kinetic ya galimoto yachepetsedwa ndi 5000 joules.
Ntchito ndi Mphamvu Zotheka
Ntchito ingayambitsenso kusintha kwa mphamvu zomwe zingatheke, makamaka m'magawo amphamvu osungira zinthu monga mphamvu yokoka kapena yamagetsi. Mu gawo la mphamvu yokoka, ntchito yochitidwa yokweza chinthu kutalika \( h \) motsutsana ndi mphamvu yokoka ndi:
\[ W = mgh \]
Kumene:
– \( m \) ndi kulemera kwa chinthucho,
– \( g \) ndi kufulumira komwe kumachitika chifukwa cha mphamvu yokoka (9,8 m/s² pamwamba pa Dziko Lapansi),
– \( h \) ndi kutalika kwa chinthucho.
Chitsanzo cha Kuwerengera Ntchito mu Gawo la Mphamvu Yokoka
Tiyerekeze kuti chinthu cholemera makilogalamu 5 chakwezedwa kufika kutalika kwa mamita awiri. Ntchito yonyamula chinthucho ndi iyi:
\[ W = mgh \]
\[ W = 5 \, \text{kg} \times 9,8 \, \text{m/s}^2 \times 2 \, \text{m} \]
\[ W = 98 \, \lemba{J} \]
Kotero, ntchito yochitidwa ponyamula chinthucho ndi ma joules 98.
Mapulogalamu Amalonda mu Moyo wa Tsiku ndi Tsiku
1. Mayendedwe: Injini ya galimoto imagwira ntchito yosuntha galimoto kuchokera pamalo ena kupita kwina. Kumvetsetsa ntchito ndi mphamvu kumathandiza popanga injini zogwira ntchito bwino.
2. Masewera: Othamanga amachita khama akamaponya mpira, kulumpha, kapena kuthamanga. Aphunzitsi amagwiritsa ntchito lingaliro la khama kuti apititse patsogolo luso la othamanga.
3. Kapangidwe ka Nyumba: Mainjiniya amagwiritsa ntchito lingaliro la khama popanga makina onyamulira katundu ndi zida zolemera zomwe zimagwiritsidwa ntchito pomanga nyumba ndi zomangamanga.
4. Mphamvu Zongowonjezedwanso: Mu ukadaulo wa mphamvu zongowonjezedwanso, monga ma turbine amphepo ndi mapanelo a dzuwa, malingaliro a ntchito ndi mphamvu amagwiritsidwa ntchito kusintha mphamvu zachilengedwe kukhala mphamvu zamagetsi.
Mapeto
Ntchito ndi lingaliro lofunikira mu fizikisi lomwe limafotokoza kusamutsa mphamvu kudzera mu mphamvu yomwe imayambitsa kusamuka. Pogwiritsa ntchito njira yoyambira \( W = F \cdot d \cdot \cos(\theta) \), titha kuwerengera ntchito yochitidwa ndi mphamvu yosasintha kapena mphamvu yosintha. Ntchito imagwirizana kwambiri ndi mphamvu ya kinetic ndi potential, ndipo ili ndi ntchito zambiri zofunika pa moyo watsiku ndi tsiku ndi ukadaulo. Kumvetsetsa bwino ntchito kumatithandiza kupanga machitidwe ogwira ntchito bwino ndikumvetsetsa zochitika zosiyanasiyana zakuthupi zomwe zimachitika mozungulira ife.
