physics

Cov vectors hauv chav tsev - teeb meem thiab kev daws teeb meem

1. Ib yam khoom txav mus los nrog lub zog ntawm v = (2i − 1.5j) m/s. Qhov kev hloov chaw ntawm yam khoom tom qab 4 vib nas this yog dab tsi?

Paub:

Qhov feem kab rov tav ntawm qhov ceev (v _x ) = 2 m/s

Qhov feem ntsug ntawm qhov ceev (v _y ) = 1.5 m/s

Lub sijhawm luv (t) = 4 vib nas this

Xav tau: Kev hloov chaw

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Kev hloov chaw ntawm vector - teeb meem thiab kev daws teeb meem

1. Ib tug neeg taug kev ntawm qhov chaw A mus rau qhov chaw B, 600 meters sab qaum teb; ces mus rau qhov chaw C, 400 meters sab hnub poob; ces mus rau qhov chaw D, 200 meters sab qab teb; thiab ces mus txog qhov chaw E, 700 meters sab hnub tuaj. Qhov kev hloov chaw loj npaum li cas?

Tshuaj:

Paub:

AB = AB – BF = AB – CD = 600 – 200 = 400 m

EF = DE – DF = DE – BC = 700 – 400 = 300 m

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Ntxiv cov vectors siv cov khoom sib xyaw - teeb meem thiab kev daws teeb meem

1. Peb lub vectors raws li qhia hauv daim duab hauv qab no.

V₁ = 30

V2 = ₃₀

V3 = ₄₀

Cov vectors uas tau los ntawm qhov no yog dab tsi.

Paub:

V ₁ = 30, lub kaum sab xis ntawm V ₁ thiab x axis = 30 ^o

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Cov duab ntawm kev txav mus los linear - teeb meem thiab kev daws teeb meem

1. Kos duab qhov deb (ntsug) piv rau lub sijhawm (kab rov tav) raws li pom hauv daim duab hauv qab no. Ib yam khoom uas so tau qhia los ntawm tus lej…

Tshuaj:

Tus lej 3, qhia los ntawm ib txoj kab ncaj.

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Qhov nruab nrab ntawm qhov ceev - teeb meem thiab kev daws teeb meem

1. Muaj ib tug neeg tig ib lub duab plaub fab uas ntev li 400 m thiab dav li 100 m, 12 zaug hauv 1 teev. Qhov ceev nruab nrab thiab qhov ceev nruab nrab yog dab tsi?

Paub:

Qhov ntev ntawm lub duab plaub fab = 400 meters

Dav ntawm lub duab plaub fab = 100 meters

Lub voj voog ntawm lub duab plaub fab = (2 x 400 meters) + (2 x 100 meters) = 800 meters + 200 meters = 1000 meters

Qhov Nrug = 12 x 1000 meters = 12,000 meters = 12 kilometers

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Txoj Cai Dub - Teeb Meem thiab Kev daws teeb meem

1. 200-gram dej ntawm 30°C sib xyaw nrog 100-gram dej ntawm 90°C. Lub cua sov tshwj xeeb ntawm dej = 1 cal.gram ⁻¹ °C ⁻¹ . Txheeb xyuas qhov kub kawg ntawm qhov sib tov!

Paub:

Qhov hnyav ntawm dej 2 (m ₁ ) = 200 grams

Kub ntawm dej 1 (T ₁ ) = 30 ^o C

Qhov hnyav ntawm dej 2 (m2 ₎ = 100 grams

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10 Dynamics Khoom txuas nrog los ntawm txoj hlua hla lub pulley Atwood tshuab - Teeb Meem thiab Kev daws teeb meem

1. Thaiv A nrog qhov hnyav 5 kg, muab tso rau ntawm ib lub dav hlau kab rov tav. Thaiv B nrog qhov hnyav 3 kg dai ntawm ib kawg ntawm txoj hlua txuas nrog thaiv A hla lub pulley. Kev nrawm vim lub ntiajteb txawj nqus yog 10 m/s ^2. Kev nrawm ntawm ob lub thaiv yog dab tsi ?

Paub:

Qhov hnyav ntawm thaiv A (m_A) = 5 kg

Qhov hnyav ntawm thaiv B (mB ₎ = 3 kg

Kev nrawm vim lub ntiajteb txawj nqus (g) = 10 m/s ²

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Kev txav mus los ncig - teeb meem thiab kev daws teeb meem

1. Ib yam khoom hnyav 10-kg txav mus los hauv ib lub voj voog nrog qhov ceev tas li 4 m/s. Yog tias lub vojvoog ntawm lub voj voog yog 0.5 meters, ces:

1) Lub zaus ntawm cov voj voog yog 4/π Hz

2) Qhov kev nrawm ntawm lub centripetal yog 32 ms ^-2

3) Lub zog centripetal yog 320 N

4) Lub sijhawm yog 4π s.

Cov lus hais twg yog cov lus tseeb?

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Kev poob qis dawb - teeb meem thiab kev daws teeb meem

1. Ib lub pob zeb poob dawb paug los ntawm qhov siab ntawm 45 meters. Yog tias qhov kev nrawm vim lub ntiajteb txawj nqus yog 10 ms ^-2 , qhov ceev ntawm lub pob zeb thaum nws ntaus hauv av yog dab tsi?

Paub:

Qhov siab (h) = 45 meters

Kev nrawm vim lub ntiajteb txawj nqus (g) = 10 m/s ²

Xav tau: Qhov ceev kawg ntawm lub pob zeb thaum nws ntaus hauv av (v _t )

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