physics

3 cov lus nug txog qhov sib txawv ntawm qhov muaj peev xwm

1. Ib lub zog hluav taws xob raug txav mus rau hauv ib lub teb hluav taws xob sib xws nrog lub zog ntawm 2√3 N ntawm qhov deb ntawm 20 cm. Yog tias qhov kev taw qhia ntawm lub zog yog nyob rau ntawm lub kaum sab xis ntawm 30 ^o rau qhov kev hloov chaw ntawm lub zog hluav taws xob, qhov sib txawv ntawm lub zog hluav taws xob ntawm qhov pib thiab qhov kawg ntawm lub zog hluav taws xob yog dab tsi.

Paub:

Lub zog (F) = 2√3 N

Qhov Nrug Deb (s) = 20 cm = 0.2 m

Lub kaum sab xis (θ) = 30 ^o

Xav tau: Qhov sib txawv ntawm lub zog hluav taws xob

tshuaj:

nyeem ntxiv

3 cov lus nug txog kev sib npaug ntawm qhov ceev ntawm lub kaum sab xis

1. Ib yam khoom uas txav mus los hauv txoj kev voj voog muaj lub vojvoog ntawm 0.5 m. Lub khoom me me no muaj peev xwm npog lub kaum sab xis ntawm 60π rad hauv 15 vib nas this. Txheeb xyuas qhov ceev ntawm lub kaum sab xis ntawm yam khoom.

Paub:

Lub vojvoog (r) = 0.5 meters

Lub kaum sab xis (θ) = 60π rad

Lub sijhawm luv (t) = 15 vib nas this

Xav tau: angular velocity (ω)

tshuaj:

nyeem ntxiv

3 cov lus nug txog qhov sib npaug ntawm lub zog tshwm sim

1. Lub tsheb uas hnyav 5 tonnes txav ntawm qhov chaw so hauv 50 vib nas this, mus txog qhov ceev ntawm 72 km / teev. Lub zog ntawm lub tsheb yog ...

Paub:

Qhov hnyav (m) = 5 tons = 5000 kg

Qhov ceev pib (vo) = 0

Qhov ceev kawg (vt) = 72 km/h = 20 m/s

Lub sijhawm luv (t) = 50 vib nas this

Xav tau: Lub zog (F)

tshuaj:

nyeem ntxiv

3 cov lus nug txog kev sib npaug ntawm Impulse

1. Ib lub tsheb uas hnyav 250 kg tab tom khiav nrog qhov ceev ntawm 72 km/teev, ces nrawm nrog lub zog tas li kom hauv 5 vib nas this nws qhov ceev dhau los ua 80 km/teev. Txheeb xyuas lub zog rau 5 vib nas this.

Paub:

Qhov hnyav ntawm lub tsheb (m) = 250 kg

Qhov ceev pib (v _o ) = 72 km/h = 20 m/s

Qhov ceev kawg (v _t ) = 80 km/h = 22 m/s

Lub sijhawm luv (t) = 5 vib nas this

Xav tau: Txheeb xyuas lub zog (I)

tshuaj:

nyeem ntxiv

3 cov lus nug txog kev sib npaug ntawm lub zog sib txhuam

1. Muab lub thaiv A hnyav 3 kg tso rau ntawm lub rooj thiab tom qab ntawd khi rau ntawm txoj hlua uas txuas nrog pob zeb B = 2 kg los ntawm lub pulley raws li qhia. Qhov hnyav thiab kev sib txhuam ntawm cov pulleys raug tsis quav ntsej. Kev nrawm vim yog lub ntiajteb txawj nqus g = 10 m/s ^2. Txheeb xyuas qhov nrawm ntawm lub kaw lus thiab qhov nruj hauv txoj hlua yog tias:

a) lub rooj du

b) cov lus qhia txog kev sib txhuam nrog tus coefficient ntawm kev sib txhuam kinetic ntawm 0.4

Paub:

Qhov hnyav ntawm thaiv A (mA ₎ = 3 kg

Qhov hnyav ntawm pob zeb B (mB ₎ = 2 kg

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

Qhov hnyav ntawm thaiv A (w _A ) = mg = (3)(10) = 30 Newtons

Qhov hnyav ntawm pob zeb B (w _B ) = mg = (2)(10) = 20 Newtons

Xav tau: Qhov kev nrawm ntawm lub kaw lus (a) thiab qhov nro hauv txoj hlua (T)

tshuaj:

nyeem ntxiv

3 cov lus nug txog kev sib npaug ntawm lub zog ib txwm muaj

1. Ib lub thaiv muaj qhov hnyav ntawm 5 kg. Yog tias g = 10 m/s2 ^, txiav txim siab:

a) qhov hnyav ntawm lub thaiv

b) lub zog ib txwm yog tias lub thaiv raug muab tso rau ntawm lub dav hlau tiaj tus

c) lub zog ib txwm yog tias lub thaiv nyob rau ntawm lub dav hlau uas tsim lub kaum sab xis ntawm 30 ^o mus rau kab rov tav

Paub:

Qhov hnyav ntawm lub thaiv (m) = 5 kg

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

Xav tau: w, N ntawm lub dav hlau thiab N ntawm lub toj

tshuaj:

nyeem ntxiv

3 Cov Lus Nug Txog Kev Sib Npaug Ntawm Txoj Hlua

1. Daim duab hauv qab no qhia peb lub thaiv, uas yog A, B thiab C uas nyob rau ntawm ib lub dav hlau kab rov tav. Yog tias qhov hnyav A = 1 kg, qhov hnyav B = 2 kg thiab qhov hnyav C = 2 kg thiab F = 10 N, ces txiav txim siab qhov piv ntawm qhov kev nruj hauv txoj hlua ntawm A thiab B rau qhov kev nruj hauv txoj hlua ntawm B thiab C.

Paub:

Qhov hnyav ntawm A (mA ₎ = 1 kg

Qhov hnyav B (mB ₎ = 2 kg

Qhov hnyav ntawm C (mC ₎ = 2 kg

Lub zog tensile (F) = 10 N

Xav tau: T _AB : T _BC

tshuaj:

nyeem ntxiv

3 Cov teeb meem thiab kev daws teeb meem txog Moment of inertia equation

1. Ib lub tog raj kheej khov kho muaj lub vojvoog ntawm 8 cm thiab qhov hnyav ntawm 2 kg. Lub sijhawm no, ib lub pob khov kho muaj lub vojvoog ntawm 5 cm thiab qhov hnyav ntawm 4 kg. Yog tias ob yam khoom tig nrog ib txoj kab hla lawv qhov chaw, txiav txim siab qhov piv ntawm lub sijhawm ntawm inertia ntawm lub tog raj kheej thiab lub pob.

Paub:

Lub vojvoog ntawm lub tog raj kheej khov kho (r) = 8 cm = 0.08 m

Qhov hnyav ntawm lub tog raj kheej khov kho (m) = 2 kg

Lub vojvoog ntawm lub pob khov kho (r) = 5 cm = 0.05 m

Qhov hnyav ntawm lub pob khoom khov kho (m) = 4 kg

Xav tau: Kev sib piv ntawm lub zog ntawm inertia ntawm lub tog raj kheej thiab lub pob

Kev daws teeb meem :

nyeem ntxiv

3 teeb meem thiab kev daws teeb meem txog Momentum equation

1. Yog tias qhov ceev ntawm yam khoom dhau los ua 5 npaug ntawm nws qhov ceev qub, ces qhov zog ntawm yam khoom dhau los ua ….. nws qhov zog qub.

Paub:

Qhov ceev pib = v

Qhov ceev kawg = 5v

Qhov hnyav = 1

Xav tau: Momentum

tshuaj:

nyeem ntxiv

3 teeb meem thiab kev daws teeb meem txog qhov sib npaug ntawm qhov ceev

1. Ib lub tsheb mus rau sab qab teb li 100 m hauv 1 feeb ces tig mus rau sab hnub tuaj li 120 m hauv 0.5 feeb. Xam qhov ceev nruab nrab ntawm lub tsheb.

Paub:

Tag nrho qhov deb = 100 meters + 120 meters = 220 meters

Tag nrho lub sijhawm = 1 feeb + 0.5 feeb = 1.5 feeb = 90 vib nas this

Xav tau: Qhov ceev nruab nrab

tshuaj:

nyeem ntxiv