Mphamvu - mavuto ndi mayankho

Mphamvu ndi liwiro limene ntchito imagwiridwa mu nthawi inayake. Mwa masamu, mphamvu ndi chiŵerengero cha ntchito/nthawi.

P = W/t

Kufotokozera: P = mphamvu (Joule/sekondi = Watt), W = ntchito (Joule), t = nthawi yopuma (sekondi)

Kutengera ndi equation iyi, tinganene kuti kuchuluka kwa ntchito, mphamvu zimakhala zazikulu. Kumbali ina, kuchepa kwa ntchito, mphamvu zimakhala zochepa. Kuchuluka kwa ntchito kumatanthauza kuchuluka kwa ntchito.

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Mphamvu ndi scalar. Gawo la SI la mphamvu ndi Joule/lachiwiri. Joule/lachiwiri = Watt (yofupikitsidwa ngati W), yomwe imatchedwa choncho polemekeza James Watt. Gawo la ufumu wa Britain la mphamvu ndi foot-pounds pa sekondi.

Chipangizochi ndi chaching'ono kwambiri kuti chigwiritsidwe ntchito, kotero chimagwiritsidwa ntchito mphamvu yayikulu ya horsepower (yofupikitsidwa ngati hp). Mphamvu imodzi ya horsepower = 550 foot-pounds pa sekondi = 764 Watts = ¾ kilowatt.

Kuchuluka kwa ntchito kungawonetsedwenso mu mayunitsi amphamvu x nthawi, mwachitsanzo, kilowatt-hours kapena kWh. KWh imodzi imatanthauza ntchito yochitidwa pamlingo wosasintha wa 1 kiloWatt kwa ola limodzi.

1. Munthu wolemera makilogalamu 50 amathamanga kukwera masitepe otalika mamita 10 m'mphindi ziwiri. Kuthamanga chifukwa cha mphamvu yokoka (g) ndi 10 m/ s . ^2. Dziwani mphamvu.

Zodziwika:

Kulemera (m) = 50 kg

Kutalika (h) = mamita 10

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

Nthawi yopuma (t) = mphindi ziwiri = 2 (60) = masekondi 120

Akufuna : Mphamvu (P)

Yankho:

Fomula ya mphamvu:

P = W / t

P = mphamvu , W = ntchito , t = nthawi

Fomula ya Ntchito:

W = F s = wh = mgh

W = ntchito , F = mphamvu , w = kulemera , d = kusamuka , h = kutalika , m = kulemera, g = kuthamanga chifukwa cha mphamvu yokoka

W = mgh = (50)(10)(10) = 5000 Joules.

P = W / t = 5000 / 120 = 41.7 Joules/se c on d.

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2. Werengani mphamvu yofunikira kwa munthu wolemera makilogalamu 60 amene akukwera mtengo wautali mamita 5 m'masekondi 10. Kuthamanga chifukwa cha mphamvu yokoka ndi 10 m/s ².

Zodziwika:

Kulemera (m) = 60 kg

Kutalika (h) = mamita awiri s

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

Nthawi yopuma (t) = masekondi 10

Akufuna : Mphamvu

Yankho:

Ntchito:

W = mgh = (60)(10)(5) = 3000 Joules

Mphamvu:

P = W / t = 3000 / 10 = 300 Joules/se cond.

3. Sewero loseketsa lozungulira lokhala ndi mphamvu ya ma watts 300 ndi mphindi 5 lozungulira ma raundi 5. Mphamvu yomwe imagwiritsa ntchito ndi….

A. 15 kJ

B. 75 kJ

C. 90 kJ

D. 450 kJ

Zodziwika:

Mphamvu (P) = 300 Watts = 300 Joules/sekondi

Nthawi (T) = mphindi 5 = 5 (masekondi 60) = masekondi 300

Chiwerengero cha maulendo = 5

Kufunidwa: Mphamvu zomwe zimagwiritsidwa ntchito ndi sewero loseketsa

Yankho:

Yankho lolondola ndi D.

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1. Ntchitoyi idachitika ndi mavuto a mphamvu ndi mayankho
2. Mavuto ndi mayankho a mphamvu zogwirira ntchito
3. Mavuto ndi mayankho a mfundo za mphamvu za makina ndi ntchito
4. Mavuto ndi mayankho a mphamvu yokoka
5. Mphamvu yomwe ingagwiritsidwe ntchito pa mavuto ndi mayankho a masika otanuka
6. Mavuto amagetsi ndi mayankho
7. Kugwiritsa ntchito mphamvu yamakina yosungira kuti munthu agwe momasuka
8. Kugwiritsa ntchito mphamvu yamakina yosungira kayendedwe ka mmwamba ndi pansi mu kayendedwe ka free fall
9. Kugwiritsa ntchito kusunga mphamvu ya makina kuti ayende pamalo opindika
10. Kugwiritsa ntchito mphamvu yamakina yosungira kuti munthu ayende pa ndege yopendekeka
11. Kugwiritsa ntchito mphamvu ya makina yosungira kuti zigwiritsidwe ntchito poyendetsa zinthu