Lub npe tom qab tus kws tshaj lij Askiv Askiv James Edward Joule, joule (J) yog ib qho ntawm cov hauv paus hauv kev ntsuas thoob ntiaj teb. Joule tau siv los ua chav ua haujlwm, lub zog, thiab cua sov, thiab tau siv dav hauv kev siv tshawb fawb. Yog tias koj xav tau koj cov lus teb hauv joules, nco ntsoov nco ntsoov siv cov txheej txheem txuj ci txuj ci. Foot-pound lossis British chav sov (BTU) tseem siv hauv qee qhov chaw, tab sis tsis yog hauv koj li kev ua hauv tsev physics.
Kauj ruam
Txoj Kev 1 ntawm 5: Xam Ua Haujlwm hauv Joules
Kauj Ruam 1. Nkag siab txog kev ua haujlwm hauv physics
Yog tias koj thawb lub npov hla ib chav, koj tau siv zog ua. Yog tias koj nqa lub thawv nce, koj kuj tau siv zog ua. Muaj ob txoj hauv kev tseem ceeb uas yuav tsum muaj nyob hauv "kev lag luam":
- Koj muab cov qauv ruaj khov.
- Lub zog no ua rau cov khoom txav mus rau qhov qub raws li lub zog.
Kauj Ruam 2. Nkag siab lub ntsiab lus ntawm kev ua lag luam
Kev rau siab yog ib qho yooj yim los laij. Tsuas yog muab tus lej quab yuam thiab tag nrho qhov kev ncua deb uas cov khoom tau mus. Feem ntau, cov kws tshawb fawb nthuav tawm quab yuam hauv Newtons thiab nrug deb li cas hauv meters. Yog tias koj siv ob qho ntawm cov chav no, chav ua haujlwm ua haujlwm yog Joules.
Thaum twg koj nyeem cov lus nug txog kev lag luam, nres thiab xav txog qhov style nyob qhov twg. Yog tias koj nqa lub npov, koj thawb nws kom lub thawv txav mus. Yog li, qhov kev ncua deb ntawm lub thawv mus ncig yog siab npaum li cas nws tau nce mus. Txawm li cas los xij, lub sijhawm tom ntej koj mus tom ntej nrog lub thawv, tsis muaj kev rau siab ua hauv txoj haujlwm no. Txawm hais tias koj tseem tab tom thawb lub thawv kom nws tsis txhob poob, nws tsis txav mus ntxiv lawm
Kauj Ruam 3. Nrhiav qhov hnyav ntawm qhov khoom raug txav chaw
Qhov hnyav ntawm ib yam khoom xav tau los laij lub zog uas yuav tsum tau txav nws. Hauv peb qhov piv txwv, xav tias lub nra hnyav 10 kg (kg).
Zam kev siv phaus lossis lwm chav uas tsis yog tus qauv, lossis koj cov lus teb kawg yuav tsis nyob hauv joules
Kauj Ruam 4. Xam cov style
Force = pawg x nrawm. Hauv peb qhov piv txwv, nqa qhov hnyav ncaj ncaj, qhov ua kom nrawm uas peb ua yog vim lub ntiajteb txawj nqus, uas nyob rau qhov xwm txheej ib txwm ua kom cov khoom qis dua ntawm 9.8 meters/sec.2. Xam lub zog xav tau kom txav peb lub nra los ntawm kev sib npaug (10 kg) x (9.8 m/s)2) = 98 kg m/s2 = 98 newtons (N).
Yog tias qhov khoom txav mus rau kab rov tav, lub ntiajteb txawj nqus tsis muaj qhov cuam tshuam. Qhov teeb meem tuaj yeem nug koj kom suav lub zog xav tau los tiv thaiv kev sib txhuam. Yog tias qhov teeb meem qhia koj txog kev nrawm ntawm cov khoom raws li nws raug thawb, koj tuaj yeem muab cov kev paub nrawm los ntawm nws qhov hnyav
Kauj Ruam 5. Ntsuas qhov kev txav chaw tau mus
Rau qhov ua piv txwv no, xav tias lub nra thauj khoom mus rau qhov siab ntawm 1.5 meters (m). Kev txav chaw yuav tsum ntsuas hauv metres, lossis koj qhov lus teb zaum kawg yuav tsis nyob hauv joules.
Kauj Ruam 6. Muab cov quab yuam los ntawm qhov txav chaw
Txhawm rau nqa 98 Newton qhov hnyav 1.5 meters siab, koj yuav tsum ua 98 x 1.5 = 147 joules ntawm kev ua haujlwm.
Kauj Ruam 7. Xam cov haujlwm uas ua kom txav cov khoom ntawm lub kaum ntse ntse
Peb qhov piv txwv saum toj no yog qhov yooj yim: ib tus neeg siv lub zog rau pem hauv ntej ntawm ib yam khoom, thiab cov khoom txav mus rau tom ntej. Qee zaum, kev taw qhia ntawm kev quab yuam thiab cov lus tsa suab ntawm cov khoom tsis zoo ib yam, vim tias muaj ntau lub zog ua rau ntawm qhov khoom. Hauv qhov piv txwv tom ntej, peb yuav xam tus naj npawb ntawm joules xav tau rau tus menyuam kom rub tus swb 25 metres hla cov daus tiaj los ntawm kev rub txoj hlua ntawm lub kaum sab xis ntawm 30º. Txog qhov teeb meem no, ua haujlwm = quab yuam x cosine (θ) x tshem tawm. Lub cim yog Greek tsab ntawv theta, thiab piav qhia lub kaum sab xis ntawm kev taw qhia ntawm lub zog thiab cov lus qhia ntawm kev txav mus los.
Kauj Ruam 8. Nrhiav tag nrho cov quab yuam siv
Txog qhov teeb meem no, xav tias tus menyuam rub hlua nrog lub zog ntawm 10 newtons.
Yog tias qhov teeb meem nthuav tawm lub zog mus rau sab xis, lub zog nce ntxiv, lossis lub zog nyob rau hauv kev taw qhia ntawm cov lus tsa suab, tom qab ntawd cov zog no tau suav rau x feem ntawm cosine (θ) ib feem ntawm lub zog, thiab koj tuaj yeem hla mus tom ntej thiab txuas ntxiv qhov txiaj ntsig
Kauj Ruam 9. Xam lub zog sib xws
Tsuas yog ob peb yam rub lub swb rau pem hauv ntej. Raws li txoj hlua tau taw tes, lwm lub zog sim rub nws, rub nws tawm tsam lub ntiajteb txawj nqus. Xam lub zog ua raws li kev taw qhia:
- Hauv peb qhov piv txwv, lub kaum sab xis ntawm lub tiaj daus thiab txoj hlua yog 30º.
- Suav cos (θ). cos (30º) = (√3)/2 = kwv yees li 0.866.
- Muab tag nrho lub zog x cos (θ). Hauv peb qhov piv txwv, 10 N x 0.866 = 8.66 rog nyob rau hauv cov lus qhia ntawm cov lus tsa suab.
Kauj Ruam 10. Muab lub zog x tshem tawm
Tam sim no peb paub lub zog uas tau nce qib hauv kev coj ua, peb tuaj yeem suav qhov haujlwm li qub. Peb qhov teeb meem qhia peb tias tus swb yuav txav mus tom ntej 20 metres, yog li xam 8.66 N x 20 m = 173.2 joules ntawm kev ua haujlwm.
Txoj Kev 2 ntawm 5: Xam Joules los ntawm Watts
Kauj Ruam 1. Nkag siab lub zog thiab lub zog
Watt yog chav ntawm lub zog lossis tus nqi siv hluav taws xob (lub zog faib ua lub sijhawm). Thaum Joule yog chav ntawm lub zog. Txhawm rau hloov Watts rau Joules, koj yuav tsum txiav txim siab lub sijhawm. Qhov ntev hluav taws xob ntws ntau dua, siv lub zog ntau dua.
Kauj Ruam 2. Muab Watts los ntawm vib nas this kom tau Joules
1 Watt ntaus ntawv yuav siv 1 Joule lub zog txhua 1 thib ob. Yog tias koj muab tus lej ntawm Watts los ntawm vib nas this, koj yuav tau txais Joules. Txhawm rau kom paub ntau npaum li cas lub zog 60W lub teeb siv hauv 120 vib nas this, koj tsuas yog xav tau los sib npaug 60 watts x 120 vib nas this = 7,200 Joules.
Cov mis no tuaj yeem siv rau txhua lub zog qhia hauv Watts, tab sis feem ntau yog hluav taws xob
Txoj Kev 3 ntawm 5: Xam Kinetic Zog hauv Joules
Kauj Ruam 1. Nkag siab txog kinetic zog
Kinetic zog yog tus nqi ntawm lub zog nyob rau hauv daim ntawv ntawm cov lus tsa suab. Ib yam li lwm lub zog, kinetic zog tuaj yeem sau ua joules.
Lub zog hluav taws xob sib npaug rau qhov ua haujlwm tau ua kom nrawm rau qhov khoom siv zoo li qub mus rau qee qhov nrawm. Thaum cov khoom mus txog qhov nrawm, cov khoom yuav tswj hwm qee yam ntawm cov khoom siv hluav taws xob kom txog thaum lub zog hloov mus ua cua sov (los ntawm kev sib txhuam), lub zog muaj peev xwm nqus (los ntawm kev tawm tsam lub ntiajteb txawj nqus), lossis lwm yam zog
Kauj Ruam 2. Nrhiav qhov hnyav ntawm qhov khoom
Piv txwv li, peb ntsuas lub zog kinetic ntawm lub tsheb kauj vab & tsheb kauj vab. Piv txwv li, tus neeg caij tsheb muaj qhov hnyav ntawm 50 kg, thiab nws lub tsheb kauj vab muaj qhov hnyav ntawm 20 kg, rau qhov hnyav tag nrho ntawm 70 kg. Tam sim no, peb txiav txim siab ob qho tib si ua ib yam khoom nrog qhov hnyav ntawm 70 kg vim tias lawv ob leeg yuav txav ntawm qhov nrawm.
Kauj Ruam 3. Xam qhov ceev
Yog tias koj twb paub qhov nrawm lossis nrawm ntawm cov neeg caij tsheb kauj vab, tsuas yog sau nws thiab txav mus ntxiv. Yog tias koj xav tau los suav qhov nrawm, siv ib qho ntawm cov hauv qab no. Nco ntsoov tias peb tab tom nrhiav nrawm, tsis nrawm (uas yog nrawm hauv qhov kev qhia), txawm hais tias cov ntawv luv v feem ntau siv. Tsis quav ntsej ib qho tig tus neeg caij tsheb kauj vab ua thiab xav tias tag nrho qhov kev ncua deb tau them rau hauv txoj kab ncaj.
- Yog tias tus neeg caij tsheb kauj vab txav mus los ntawm qhov nrawm (tsis nrawm dua), ntsuas qhov nrug tus neeg caij tsheb kauj vab taug kev hauv meters, thiab faib los ntawm tus lej nws yuav siv los npog qhov nrug ntawd. Qhov kev xam no yuav tawm los qhov nruab nrab nrawm, uas hauv qhov no yog sib npaug rau qhov nrawm nrawm.
- Yog tias cov neeg caij tsheb kauj vab ntsib kev nrawm nrawm thiab tsis hloov pauv, suav nws qhov nrawm ntawm lub sijhawm t siv cov qauv rau kev nrawm ntawm lub sijhawm t = (nrawm) (t) + pib nrawm. Siv thib ob los ntsuas lub sijhawm, ntsuas/feeb thib ob los ntsuas nrawm, thiab m/s2 los ntsuas kev nrawm.
Kauj Ruam 4. Txuas cov lej no rau hauv cov lej hauv qab no
Kinetic zog = (1/2) m v 2. Piv txwv li, yog tias tus neeg caij tsheb kauj vab txav mus nrawm li 15 m/s, nws lub zog siv hluav taws xob EK = (1/2) (70 kg) (15 m/s)2 = (1/2) (70 kg) (15 m/s) (15 m/s) = 7875 kgm2/s2 = 7875 newton meter = 7875 joules
Cov mis rau kinetic zog tuaj yeem muab los ntawm lub ntsiab lus ntawm kev ua haujlwm, W = FΔs, thiab kinematic equation v2 = v02 + 2 ua. s sawv cev rau kev hloov pauv ntawm txoj haujlwm lossis kev nrug deb.
Txoj Kev 4 ntawm 5: Xam Xauv Kub hauv Joules
Kauj Ruam 1. Nrhiav qhov hnyav ntawm qhov khoom ua kom sov
Siv qhov ntsuas lossis qhov sib npaug ntawm lub caij nplooj ntoo hlav los ntsuas nws. Yog tias cov khoom yog kua, ua ntej ntsuas lub ntim khoob uas cov kua yog thiab pom nws qhov hnyav. Koj yuav tsum rho nws los ntawm qhov ntim ntawm cov ntim ntxiv rau cov kua kom pom qhov hnyav ntawm cov kua. Txog qhov piv txwv no, cia peb hais lub hom phiaj yog 500 grams dej.
Siv grams, tsis yog lwm chav, lossis qhov txiaj ntsig yuav tsis yog joules
Kauj Ruam 2. Nrhiav cov cua sov tshwj xeeb ntawm cov khoom
Cov ntaub ntawv no tuaj yeem nrhiav tau hauv kev siv tshuaj lom neeg, ob leeg hauv phau ntawv thiab online. Txog dej, qhov kub tshwj xeeb ntawm c yog 4.19 joules ib gram rau txhua qib Celsius nws tau sov - lossis 4.1855, yog tias koj xav tau tus nqi tseeb.
- Qhov tseeb tshwj xeeb cua sov sib txawv me ntsis raws qhov kub thiab txias. Cov koom haum sib txawv thiab cov ntawv kawm siv cov qauv ntsuas sib txawv, yog li koj tuaj yeem pom cov dej sov tshwj xeeb teev raws li 4.179.
- Koj tuaj yeem siv Kelvin hloov chaw Celsius vim qhov sib txawv ntawm qhov kub tau zoo ib yam rau ob chav (ua kom sov ib yam los ntawm 3ºC sib npaug cua sov los ntawm 3 Kelvin). Tsis txhob siv Fahrenheit, lossis koj cov txiaj ntsig yuav tsis nyob hauv joules.
Kauj Ruam 3. Nrhiav thawj qhov kub ntawm qhov khoom
Yog tias cov khoom yog kua, koj tuaj yeem siv tus pas ntsuas kub uas muaj mercury. Rau qee yam khoom, koj yuav xav tau tus ntsuas kub ntsuas.
Kauj Ruam 4. Ua kom sov cov khoom thiab ntsuas qhov kub dua
Qhov no yuav ntsuas qhov kub nce ntawm qhov khoom thaum cua sov.
Yog tias koj xav ntsuas tag nrho lub zog khaws cia ua cua sov, koj tuaj yeem xav tias qhov ntsuas kub pib yog qhov tsis txaus: 0 Kelvin lossis -273.15ºC. Qhov no tsis muaj txiaj ntsig zoo
Kauj Ruam 5. Tshem tawm qhov pib qhov kub los ntawm qhov ntsuas cua sov
Qhov txo qis no yuav ua rau muaj qhov hloov pauv ntawm qhov kub ntawm qhov khoom. Piv txwv tias dej yav dhau los 15 degrees Celsius thiab rhaub kom 35 degrees Celsius, qhov kub hloov mus rau 20 degrees Celsius.
Kauj Ruam 6. Muab cov khoom sib npaug sib npaug los ntawm nws cov cua sov tshwj xeeb thiab los ntawm qhov hloov pauv ntawm qhov kub thiab txias
Cov mis tau sau Q = mc T, qhov twg T yog qhov hloov pauv ntawm qhov kub thiab txias. Rau qhov piv txwv no, nws yuav yog 500g x 4, 19 x 20, lossis 41,900 joules.
Cov cua sov feem ntau sau hauv cov calories lossis kilocalorie metric system. Cov calories tau teev tseg raws li cov cua sov xav tau txhawm rau nce qhov kub ntawm 1 gram dej los ntawm 1 degree Celsius, thaum kilocalorie yog qhov kub xav tau kom nce qhov kub ntawm 1 kilogram ntawm dej los 1 degree Celsius. Hauv qhov piv txwv saum toj no, nce qhov kub ntawm 500 grams dej los ntawm 20 degrees Celsius yuav siv li 10,000 calories lossis 10 kilocalories
Txoj Kev 5 ntawm 5: Xam Joules ua Hluav Taws Xob
Kauj Ruam 1. Siv cov kauj ruam hauv qab no los laij lub zog ntawm lub zog hluav taws xob
Cov theem hauv qab no tau teev tseg ua piv txwv piv txwv, tab sis koj kuj tseem tuaj yeem siv txoj hauv kev los nkag siab cov teeb meem kev sau ntawv. Ua ntej, peb yuav suav lub zog P siv cov mis P = I2 x R, qhov twg kuv yog tam sim no hauv amperes thiab R yog qhov tsis kam hauv ohms. Cov koog no tsim lub zog hauv watts, yog li ntawm no, peb tuaj yeem siv cov qauv hauv cov kauj ruam dhau los los xam lub zog hauv joules.
Kauj Ruam 2. Xaiv tus tiv thaiv
Resistors raug ntsuas hauv ohms, nrog qhov ntau thiab tsawg sau ncaj qha lossis sawv cev los ntawm kev sau cov kab xim. Koj tseem tuaj yeem sim qhov kev tiv thaiv ntawm tus tiv thaiv los ntawm kev txuas nws nrog ohmmeter lossis multimeter. Rau qhov piv txwv no, peb xav tias tus tiv thaiv yog 10 ohms.
Kauj Ruam 3. Txuas tus resistor mus rau qhov chaw tam sim no
Koj tuaj yeem txuas cov xov hlau mus rau tus tiv thaiv nrog Fahnestock lossis tus nab kuab, lossis koj tuaj yeem ntsaws tus tiv thaiv rau hauv pawg thawj coj saib.
Kauj Ruam 4. Dej ntws tam sim no los ntawm lub Circuit Court rau lub sijhawm luv
Rau qhov piv txwv no, peb yuav siv sijhawm li ntawm 10 vib nas this.
Kauj Ruam 5. Ntsuas lub zog tam sim no
Ua qhov no nrog ammeter lossis multimeter. Cov tsev neeg feem ntau tau ntsuas hauv milliamperes, lossis ntau txhiab amperes, yog li peb xav tias tam sim no yog 100 milliamperes lossis 0.1 amperes.
Kauj Ruam 6. Siv cov mis P = I2 x rov r.
Txhawm rau nrhiav lub zog, sib npaug cov xwm txheej ntawm qhov tam sim no los ntawm qhov tsis kam. Qhov no ua rau lub zog tso tawm hauv watts. Squaring 0.1 muab qhov tshwm sim ntawm 0.01, sib npaug los ntawm 10 muab lub zog tso tawm ntawm 0.1 watts lossis 100 milliwatts.
Kauj Ruam 7. Muab lub zog faib ua lub sijhawm dhau los
Qhov sib npaug no muab lub zog tso tawm hauv joules. 0.1 watt x 10 vib nas this yog sib npaug rau 1 joule ntawm lub zog hluav taws xob.
