Kev sib tsoo - teeb meem thiab kev daws teeb meem

Kev sib tsoo - teeb meem thiab kev daws teeb meem

1. Khoom A (3 kg) txav mus nrog qhov ceev ntawm 8 m/s thiab khoom B (5 kg) txav mus nrog qhov ceev ntawm 4 m/s. Yog tias qhov kev sib tsoo ntawm cov khoom A thiab B yog qhov ywj pheej zoo kawg nkaus, qhov twg yog? tshaj tawm ntawm cov khoom A thiab B tom qab kev sib tsoo?

Paub:

Pawg ntawm yam khoom A (m₁) = 3 kg

Qhov hnyav ntawm yam khoom B (m₂) = 5 kg

cov ceev ntawm yam khoom A (v₁) = 8 ms^-1

Qhov ceev ntawm yam khoom B (v)₂) = 4 ms^-1

Kev sib tsoo zoo kawg nkaus elastic.

SE pob: v₁' thiab v₂'

Tshuaj:

Yog tias ob yam khoom muaj qhov hnyav sib txawv thiab qhov ceev ntawm ob yam khoom tom qab kev sib tsoo tseem tsis tau paub, ces qhov ceev tom qab kev sib tsoo raug suav los ntawm kev siv cov qauv no:

Qhov kev taw qhia ntawm ob yam khoom yog tib yam yog li qhov ceev ntawm ob yam khoom muaj tib lub cim. Yog tias ob yam khoom txav mus rau hauv kev taw qhia sib txawv ces ib qho ceev muaj lub cim ntxiv thiab lwm qhov ceev muaj lub cim rho tawm.

Qhov ceev ntawm yam khoom A (v)_A) tom qab kev sib tsoo:

Qhov ceev ntawm yam khoom B (v)_B) tom qab kev sib tsoo:

Qhov ceev ntawm yam khoom A (v₁') tom qab sib tsoo yog 3 m/s thiab qhov ceev ntawm yam khoom B (v₂') tom qab sib tsoo yog 7 m/s.

2. Lub pob muaj lub zog ntawm P, sib tsoo nrog phab ntsa thiab raug cuam tshuam. Qhov kev sib tsoo yog elastic zoo kawg nkaus thiab nws qhov kev taw qhia perpendicular rau phab ntsa. Qhov kev hloov pauv ntawm lub pob yog dab tsi? momentum?

Paub:

Qhov hnyav ntawm lub pob = m

Qhov ceev ntawm lub pob ua ntej sib tsoo = v

Qhov ceev ntawm lub pob tom qab sib tsoo = -v (lub pob cuam tshuam rau sab laug)

Lub zog ntawm lub pob ua ntej sib tsoo (p_o) = mv

Lub zog ntawm lub pob tom qab kev sib tsoo (p_t) = m (-v) = – mv

SE pob: Qhov kev hloov pauv ntawm lub zog ntawm lub pob

Tshuaj:

Kev hloov pauv ntawm lub zog:

Δp = p_t – p_o

Δp = – mv – mv

Δp = – 2 mv

Δp = -2p

Lub cim rho tawm qhia txog kev taw qhia ntawm lub pob.

3. Ob yam khoom, A thiab B, muaj tib lub cev hnyav txav mus rau sab nraud thiab sib tsoo. A txav mus rau sab hnub tuaj nrog qhov ceev V thiab B txav mus rau sab hnub poob nrog qhov ceev 2V. Yog tias qhov kev sib tsoo yog elastic tag nrho, ces qhov ceev ntawm ob yam khoom yog dab tsi tom qab kev sib tsoo.

Paub:

Ob yam khoom muaj tib qhov hnyav.

A txav mus rau sab hnub tuaj nrog qhov ceev ntawm V

B txav mus rau sab hnub poob nrog qhov ceev ntawm 2V

SE pob: Qhov ceev ntawm ob yam khoom tom qab kev sib tsoo

Tshuaj:

Yog tias ob yam khoom muaj tib lub cev hnyav thiab qhov kev sib tsoo yog elastic zoo kawg nkaus, ces tom qab kev sib tsoo ob yam khoom hloov lawv qhov ceev.

Tom qab kev sib tsoo, A txav mus rau sab hnub poob ntawm 2V thiab B txav mus rau sab hnub tuaj ntawm V.

Kev Sib Tsoo Ib Nrab Elastic

4. Ob yam khoom uas muaj tib lub cev hnyav txav mus raws ib txoj kab ncaj nraim rau hauv cov kev taw qhia sib txawv raws li pom hauv daim duab hauv qab no. Yog tias qhov ceev ntawm yam khoom 2 tom qab kev sib tsoo (v₂') yog 5 m/s mus rau sab xis, ces qhov loj ntawm qhov ceev ntawm yam khoom 1 tom qab kev sib tsoo yog dab tsi.

Paub:

Qhov hnyav ntawm txhua yam khoom = m

Qhov ceev ntawm yam khoom 1 ua ntej sib tsoo (v₁) = 8 m/s

Qhov ceev ntawm yam khoom 2 tom qab sib tsoo (v₂) = 10 m/s

Qhov ceev ntawm yam khoom 2 tom qab sib tsoo (v₂') = 5 m/s

Xav tau: Qhov ceev ntawm yam khoom 1 tom qab sib tsoo (v₁')

Tshuaj:

Qhov kev sib tsoo yog ib feem elastic.

m₁ v₁+m₂ v₂ = kuv₁ v₁' + m₂ v₂'

m (v)₁ +v₂) = m(v)₁' + v₂')

v₁ +v₂ = v₁' + v₂'

8 + 10 = v₁' + 5

18 = v₁' + 5

v₁' = 18-5

v₁' = 13 m/s

Kev sib tsoo tsis sib luag

5. Ib lub mos txwv hnyav 10-gram raug tua ntawm 100 ms^-1 , tsoo ib lub thaiv ntoo thaum tsis txav. Qhov hnyav ntawm lub thaiv yog 490 grams. Qhov kev sib tsoo tsis sib luag. Qhov ceev ntawm lub thaiv thiab lub mos txwv tom qab sib tsoo yog dab tsi.

Paub:

qhov hnyav ntawm lub mos txwv (m₁) = 10 grams

Qhov ceev ntawm lub mos txwv (v₁) = 100 m/s

Qhov hnyav ntawm lub thaiv (m₂) = 490 grams

Kev ceev ntawm thaiv (v₂) = 0 m/s (thaiv thaum so)

Xav tau: Qhov ceev ntawm lub thaiv thiab lub mos txwv tom qab sib tsoo

Tshuaj:

m₁ v₁ +m₂ v₂ = (m₁ +m₂) v'

(10)(100) + (490)(0) = (10 + 490) v'

1000 + 0 = 500 v'

1000 = 500 v'

v' = 1000 / 500

v' = 2 m/s

6. Lub tsheb thauj khoom uas tsav nrog 10 m/s sib tsoo nrog lub tsheb uas tsav nrog 20 m/s. Tom qab sib tsoo, ob lub tsheb thauj khoom thiab lub tsheb txav mus ua ke nrog tib qhov ceev. Qhov hnyav ntawm lub tsheb thauj khoom yog 1400 kg thiab qhov hnyav ntawm lub tsheb yog 600 kg. Qhov ceev ntawm lub tsheb thauj khoom thiab lub tsheb tom qab sib tsoo yog dab tsi.

Paub:

qhov ceev ntawm lub tsheb thauj khoom (v)₁) = 10 m/s

qhov ceev ntawm lub tsheb (v)₂) = 20 m/s

qhov hnyav ntawm lub tsheb thauj khoom (m₁) = 1400 kg

qhov hnyav ntawm lub tsheb (m₂) = 600 kg

Xav tau: Qhov ceev ntawm ob lub tsheb thauj khoom thiab lub tsheb tom qab kev sib tsoo

Tshuaj:

m₁ v₁ +m₂ v₂ = (m₁ +m₂) v

(1400) (10) + (600) (20) = (1400 + 600) v

14000 + 12000 = 2000 v

26000 = 2000 v

v = 13 m/s

7. Ib lub mos txwv hnyav 20-gram txav mus rau 10 m/s hauv ib qho kev taw qhia kab rov tav, tsoo nrog ib lub pob zeb hnyav 60-gram uas nyob hauv pem teb. Tom qab sib tsoo, lub mos txwv thiab lub pob zeb txav mus ua ke nrog tib qhov ceev thiab tib qho kev taw qhia. Qhov ceev ntawm ob lub mos txwv thiab cov pob zeb yog dab tsi.

Paub:

Qhov hnyav ntawm lub mos txwv (m_P) = 20 grams = 0.02 kg

Qhov hnyav ntawm lub thaiv (m_B) = 60 grams = 0.06 kg

Qhov ceev pib ntawm lub mos txwv (v)_P) = 10 m/s

Qhov ceev pib ntawm lub thaiv (v_B= 0 TZS

Xav tau: Qhov ceev ntawm lub mos txwv thiab lub thaiv tom qab sib tsoo (v')

Tshuaj:

Qhov kev sib tsoo tsis sib haum.

m_P v_P +m_B v_B = (m_P +m_B) v'

(0.02)(10) + (0.06)(0) = (0.02 + 0.06) v'

0.2 + 0 = 0.08 v'

0.2 = 0.08 v'

v' = 0.2 / 0.08

v' = 2.5 m/s

8. Ob yam khoom, A thiab B, muaj tib lub cev hnyav = 1.5 kg mus ze rau ib leeg thiab sib tsoo. Qhov ceev ntawm yam khoom A (v_A) = 4 m/s thiab qhov ceev ntawm yam khoom B (v_B) = 5 m/s. Yog tias qhov kev sib tsoo tsis sib luag, qhov ceev ntawm ob yam khoom tom qab kev sib tsoo yog dab tsi.

Paub:

Qhov hnyav ntawm yam khoom A (m_A) = 1.5 kg

Qhov hnyav ntawm yam khoom B (m_B) = 1.5 kg

Qhov ceev ntawm yam khoom A ua ntej sib tsoo (v_A) = 4 m/s (zoo rau sab xis)

Qhov ceev ntawm yam khoom B ua ntej sib tsoo (v_B) = -5 m/s (tsis zoo rau sab laug)

Xav tau: Qhov ceev ntawm ob yam khoom tom qab sib tsoo

Tshuaj:

m_A v_A +m_B v_B = (m_A +m_B) v'

(1.5)(4) + (1.5)(-5) = (1.5 + 1.5) v'

6 – 7.5 = (3) v'

-1.5 = (3) v'

v' = -1.5 / 3

v' = -0.5 m/s

Lub cim rho tawm qhia tias tom qab sib tsoo, ob qho khoom txav mus rau sab laug, tib qho kev taw qhia li khoom B.

1. Kev sib tsoo hauv cov ntsiab lus ntawm physics yog dab tsi? tebHauv kev tshawb fawb txog physics, kev sib tsoo yog hais txog qhov xwm txheej uas ob lossis ntau yam khoom sib chwv ze rau ib leeg, feem ntau siv lub zog rau ib leeg, ua rau muaj kev sib pauv zog thiab lub zog.
2. Cov kev sib tsoo elastic thiab inelastic sib txawv li cas? tebHauv kev sib tsoo uas ywj pheej, ob qho tib si lub zog thiab lub zog kinetic raug khaws cia. Hauv kev sib tsoo tsis ywj pheej, lub zog momentum raug khaws cia, tab sis lub zog kinetic tsis yog. Kev sib tsoo tsis ywj pheej zoo meej yog ib pawg me me uas cov khoom sib tsoo lo rau ua ke tom qab kev sib tsoo.
3. Vim li cas lub zog thiaj li khaws cia tas li thaum muaj kev sib tsoo? tebLub zog tseem khaws cia rau hauv kev sib tsoo vim yog txoj cai ntawm kev khaws lub zog, uas hais tias lub zog tag nrho ntawm lub kaw lus kaw tseem ruaj khov tshwj tsis yog tias muaj cov zog sab nraud ua rau.
4. Puas yog lub zog kinetic ib txwm khaws cia thaum muaj kev sib tsoo? tebTsis yog, lub zog kinetic tsuas yog khaws cia rau hauv kev sib tsoo elastic. Hauv kev sib tsoo inelastic, qee lub zog kinetic raug hloov mus rau lwm hom zog, xws li lub zog muaj peev xwm, suab, lossis cua sov.
5. Vim li cas ob lub tsheb thiaj li lo rau ua ke tom qab sib tsoo? tebYog tias ob lub tsheb sib tsoo ua ke tom qab muaj kev sib tsoo, nws yog ib qho piv txwv ntawm kev sib tsoo tsis sib luag. Cov tsheb tseem nyob ua ke vim yog kev sib txuas ntawm lub cev, kev hloov pauv, lossis lwm yam zog uas kov yeej lawv lub peev xwm rov qab los ntawm ib leeg.
6. Ib yam khoom uas raug sib tsoo puas hloov pauv lub zog kinetic txawm tias nws qhov ceev tseem tsis hloov pauv? tebYog, yog tias ib yam khoom hloov nws txoj kev thaum lub sijhawm sib tsoo tab sis tsis hloov nws qhov ceev, nws qhov ceev (qhov ntau vector) hloov, tab sis nws qhov ceev (qhov ntau scalar) tseem zoo li qub. Txawm hais tias qhov loj ntawm nws lub zog kinetic (nyob ntawm qhov ceev) yuav tsis hloov, yam khoom tau hloov pauv hauv kev faib zog.
7. Vim li cas cov pob billiard thiaj li dhia tawm thaum lawv sib tsoo? tebCov pob billiard yuav luag sib tsoo yooj yim. Thaum ib lub pob ntaus lwm lub, lub zog kinetic thiab momentum raug hloov pauv, ua rau cov pob dhia sib nrug. Tus qauv tsim thiab cov khoom siv ntawm cov pob billiard ua rau lawv txuag tau lub zog kinetic hauv cov kev sib cuam tshuam no.
8. Yog tias ob yam khoom uas muaj qhov hnyav sib txawv sib tsoo thiab lo ua ke, lawv qhov ceev ua ke puas yuav yog qhov nruab nrab ntawm lawv qhov ceev pib? tebTsis tas li ntawd xwb. Qhov ceev ua ke yuav nyob ntawm txoj cai ntawm kev txuag lub zog. Yog tias ib yam khoom loj dua lwm yam, qhov ceev ua ke yuav ze rau qhov ceev pib ntawm yam khoom loj dua.
9. Hauv lub ntiaj teb tiag tiag, puas muaj kev sib tsoo "elastic" tiag tiag? tebHauv kev xyaum, tsis muaj kev sib tsoo twg zoo tag nrho. Txawm hais tias qee qhov kev sib tsoo, zoo li cov ntawm cov pob billiard, los ze, yeej ib txwm muaj qee lub zog poob rau lwm hom, xws li suab lossis cua sov.

10. Lub hnab cua txo qhov cuam tshuam ntawm kev sib tsoo hauv kev sib tsoo tsheb li cas? tebCov hnab cua ua rau lub zog ntawm tus neeg hloov pauv sai dua thaum muaj kev sib tsoo. Thaum ua li ntawd, lub zog uas tus neeg ntawd ntsib (uas yog sib piv rau lub sijhawm uas lub zog hloov pauv) raug txo qis, txo qhov kev raug mob.