Cov mis ntawm "Ceev, lub sij hawm, nyob deb li." Yuav ua li cas los daws kom tau qhov teeb meem?

Cia tsev kawm ntawv physics zaj lus qhia tig mus rau hauv ib qho exciting kev ua si! Nyob rau hauv no tsab xov xwm, peb heroine yuav cov mis ntawm "Ceev, lub sij hawm, nyob deb li." Cais nyias txhua parameter, peb muaj ib co nthuav tus piv txwv.

ceev

Yuav ua li cas yog lub "ceev"? Koj yuav saib tau npaum li cas ib lub tsheb mus ceev, lwm yam yog ib tug maj mam; ib tug txiv neej hais lus khiav ceev, lwm - tsis nyob rau hauv ib tug hurry. Cyclists kuj mus nyob rau txawv speeds. Yes! Hais tias tus nqi. Dab tsi yog meant los ntawm nws? Ntawm cov hoob kawm, qhov kev ncua deb uas yog ib tug txiv neej. Kuv tsav tsheb mus rau lub tsheb rau ib co sij hawm. Xav hais tias hais tias ib tug neeg ceev 5 km / h. Qhov ntawd yog ib tug 1-teev, nws yog 5 kilometers.

Yuav ua li cas mus nrhiav tau cov kev ceev, lub sij hawm, nyob deb li? Peb pib nrog ceev. Saib ze ze, yog dab tsi nws yog ntsuas? Lawm, km / h m / s. Nws muaj lwm yam units, e.g., km / s (nyob rau hauv qhov chaw), mm / h (nyob rau hauv biochemistry). Xyuam xim rau dab tsi sawv nyob rau hauv pem hauv ntej ntawm "/" kos npe rau thiab tom qab. Ua ntej, nws txhais tau tias "yob", uas txhais tau tias cov numerator - hli, km, m, nyob rau hauv lub denominator - h, s, min. Secondly, no mas, qhov no yog reminiscent ntawm cov mis, tsis yog nws? Kilometers, meters - qhov kev ncua deb, ntev, thiab lub teev, thib ob, feeb - lub sij hawm. Yog li ntawd ntau npaum li cas rau qhov taub. Nws yog yooj yim yuav tsum nco ntsoov yuav ua li cas nrhiav tau cov kev ceev, saib tsis muaj tsev (km / h, m / s). Lo lus nyob ib leeg:

v = S / t = km / h.

lub sij hawm

Yuav ua li cas yog lub sij hawm? Ntawm cov hoob kawm, nws yog nyob rau hauv lub ceev. Piv txwv li, koj yog tos rau lub chaw pib ntawm lub tsev niam thiab tus tij laug. Lawv taug kev tawm ntawm lub khw. Tij Laug tuaj npaum li cas lawm. Niam yuav tsum tau tos txog 5 feeb vim li cas? Vim hais tias lawv tau nyob hauv ib txawv npaum li cas. Ntawm cov hoob kawm, kom sai tau mus rau koj lo lus uas peb, koj yuav tsum mus ntxiv ceev rau accelerate lub txav mus rau muab tso rau siab rau lub "gas" nyob rau hauv lub tsheb nyuaj, yuav tsum tau dispersed rau ib tug lub tsheb kauj vab. Tsuas yog thaum lub maj, tsum tau ceev faj thiab tsev thiaj li tsis rau cov thawv mus rau hauv ib tug neeg los yog ib yam dab tsi.

Yuav ua li cas mus nrhiav tau lub sij hawm? Peb muaj ib tug ntsis ceev - km / h. Thiab yuav ua li cas yuav nrog lub sij hawm? Ua ntej, lub sij hawm yog ntsuas nyob rau hauv feeb, vib nas this, teev. Cov mis ntawm "ceev, lub sij hawm, nyob deb li" yog hloov raws li nram no:

lub sij hawm t [sec., min., hr] = S [m, mm, km] / v [m / s, mm / min, km / h].

Yog hais tias koj hloov ib feem ntawm tag nrho cov kev cai ntawm kev kawm txog zauv, kom qhov kev ncua deb parameter (ntev), nws tseem tsuas ib tug thib ob, feeb los yog teev.

Ze, txoj kev ntev traversed

Ntawm no nws yuav yooj yim rau next, feem ntau yuav, cov neeg tsav tsheb uas muaj ib qho chaw twg odometer nyob rau hauv ib lub tsheb. Lawv yuav tsum tau los mus txiav txim yuav ua li cas muaj ntau yam kilometers mus, tab sis kuj paub ceev. Tab sis raws li lub zog sis tsis ncaj, ces teem tonoe cov kev khiav tawm tsis ua hauj lwm, tshwj tsis yog tias peb coj tus nruab nrab ceev.

Formula txoj kev (deb) - cov khoom ntawm kev tshaj tawm thiab lub sij hawm. Ntawm cov hoob kawm, feem ntau yooj yim thiab pheej yig xaiv - nws yog lub sij hawm. Lub moos yog rau tag nrho cov. neeg taug kev ceev yog tsis nruj me ntsis 5 km / h, thiab kwv yees li. Yog li ntawd, tej zaum yuav muaj ib qho yuam kev. Nyob rau hauv cov ntaub ntawv uas, koj yuav zoo dua coj ib daim ntawv qhia ntawm lub cheeb tsam. Nco ntsoov dab tsi teev. Nws yuav tsum tau qhia ntau npaum li cas kilometers los yog meters nyob rau hauv 1 cm. Muab ib tug pas ntsuas thiab ntsuas qhov ntev. Piv txwv li, los ntawm lub tsev mus rau cov suab paj nruag lub tsev kawm ntawv ncaj txoj kev. Ya A tau muab 5 cm nyob rau hauv lub scale qhia 1 cm = 200 m txhais tau tias lub tiag tiag deb - .. 200 * 5 = 1000 m = 1 km. Yuav ua li cas npaum li cas koj mus rau hauv lub deb? Rau ib nrab ib teev? Technically hais lus, 30 = 0.5 min h = (1/2) teev. Yog hais tias peb yuav daws tau qhov teeb meem, nws hloov tawm hais tias mus rau tus ceev ntawm 2 km / h. Yuav yuav pab daws tau qhov teeb meem ntawm lub mis "tus ceev, lub sij hawm, nyob deb li."

Tsis nco!

Kuv qhia rau koj kom tsis txhob nco lub tseem ceeb heev cov ntsiab lus. Thaum koj muab ib tug neeg ua hauj lwm, yuav attentive nyob rau hauv dab tsi rau lwm cov muab tsis. Txog cov teeb meem Sau tau khib lav tau. Nws sau nyob rau hauv ib tug muab:

Tus txiv neej tsav ntawm tus ciav rau lub tsheb tuam 2 kilometers nyob rau hauv 15 feeb. Tsis txhob maj tam sim ntawd kom daws tau qhov teeb meem siv cov mis, txwv tsis pub koj tau txais tsis muaj dab tsi, koj thiab tus kws qhia ntawv nws yuav tsis suav. Nco ntsoov hais tias nyob rau hauv txhua rooj plaub nws yog tsis yooj yim sua kom ua li ntawd: 2 km / 15 min. Koj yuav tau txais lub tsev ntawm qhov kev ntsuas km / m, tsis km / h. Koj yuav tsum mus cuag lub caij nyoog kawg no. Teem lub feeb nyob rau hauv lub moos. Yuav ua li cas yuav ua rau nws? 15 feeb -. Nws yog 1/4 teev los yog 0.25 teev tau tam sim no yam xyuam xim 2km / 0,25ch = 8 km / h. Tam sim no qhov teeb meem tau daws kom raug.

Qhov ntawd yog ib qho yooj yim uas yuav tau nco mis "ceev, lub sij hawm, nyob deb li." Cia li ua raws tag nrho cov kev cai ntawm kev kawm txog zauv, xyuam xim rau cov chav nyob rau hauv lub qhov teeb meem. Yog hais tias muaj yog nuances, zoo li nyob rau hauv lub saum toj no piv txwv saum toj no cia, tam sim ntawd txhais nyob rau hauv SI units, raws li yuav tsum.