Cov Teeb Meem Tau Daws Hauv Kev Kawm Txog Physics Yooj Yim

9 Hloov cov nplai kub (Celsius nplai Fahrenheit nplai Kelvin)

1. 50 ^° C = ….. ^° F ?

tshuaj

Ntawm qhov siab ntawm huab cua ib txwm muaj , qhov chaw khov ntawm dej yog 0 ^o C ntawm qhov ntsuas Celsius thiab 32 ^o F ntawm qhov ntsuas Fahrenheit. Ntawm qhov siab ntawm huab cua ib txwm muaj, qhov chaw npau ntawm dej yog 100 ^o C ntawm qhov ntsuas Celsius thiab 212 ^o F ntawm qhov ntsuas Fahrenheit.

0 ^o C = 32 ^o F thiab 1 00 ^o C = 212 ^o F. Kev hloov ntawm 5 Co ⁼ kev hloov ntawm 9 ^F.

Rau qhov ntsuas Celsius, qhov nrug ntawm 0 ^o C thiab 100 ^o C muab faib ua 100 qhov sib npaug. Rau qhov ntsuas Fahrenheit, qhov nrug ntawm 0 ^o C thiab 100 ^o C muab faib ua 180 qhov sib npaug.

ToF = (180/100) ^ToC + ³²

ToF = (9/5) ^ToC + ³²

ToF = (9/5) 50 + ³²

ToF = (9) 10 ⁺ 32

ToF = 90 ⁺ 32

ToF = ¹²²

50 ^oC = 122 ^oF

[irp]

2. 86 ^° F = ….. ^° C ?

tshuaj

ToC ⁼ (100/180)(ToF ^– 32)

ToC ⁼ (5/9)(ToF ^– 32)

ToC = (5/9)(86 – 32 ⁾

ToC = (5/9)(54 ⁾

ToC = (5)(6 ⁾

ToC = ³⁰

86 ^o F = 30 ^o C

3. 50 ^oC = ….. K ?

tshuaj

T = ToC ⁺ 273

T = 50 + 273

TXL = 323

50 ^oC = 323 K

[irp]

4. 212 ^o F = ….. K ?

tshuaj

ToC ⁼ (100/180)(ToF ^– 32)

ToC ⁼ (5/9)(ToF ^– 32)

ToC = (5/9)(212 – 32 ⁾

ToC = (5/9)(180 ⁾

ToC = (5)(20 ⁾

ToC = ¹⁰⁰

212 ^° F = 100 ^° C + 273

212 ^o F = 373 K

 

5. ^xoC = ^xoF​

x = ….. ?

tshuaj

1: Hloov Celsius nplai rau Fahrenheit nplai

2: Hloov Fahrenheit mus rau Celsius

[irp]

6. 122°F = ….. Celsius

tshuaj

Qhov kev hloov pauv ntawm ob qhov ntsuas kub tuaj yeem sau ua:

TC ₌ 5/9 (TF _– 32)

TC = Kub hauv Celsius, TF _{= kub} hauv Fahrenheit

Qhov kub hauv Celsius:

TC = _5/9 (122 – 32) = TC ₌ 5/9 (90) = 5 (10)

TC = 50 ^oC_​

7. Daim duab hauv qab no qhia txog kev ntsuas kub ntawm cov kua dej nrog lub ntsuas kub Fahrenheit! Yog tias ntsuas qhov kub ntawm cov kua dej siv lub ntsuas kub Celsius, ces qhov kub ntawm cov kua dej yog dab tsi?

Paub:

Fahrenheit nplai (T _F ) = 95 ^o F

Xav tau: Celsius nplai

Tshuaj:

Ntawm lub siab ntawm 1 atm, qhov chaw khov ntawm dej yog 0 ° C thaum lub Fahrenheit nplai yog 32 ^o F. Ntawm qhov tod tes, qhov chaw npau ntawm dej rau lub Celsius nplai yog 100 ^o C thaum lub Fahrenheit nplai yog 212 ^o F.

Ntawm qhov ntsuas Celsius, ntawm 0 ° C thiab 100 ° C muaj 100 ° thaum ntawm qhov ntsuas Fahrenheit ntawm 32 ° F thiab 212 ° F muaj 180 °.

TC ₌ 100/180 (TF _– 32)

TC ₌ 5/9 (TF _– 32)

TC ₌ 5/9 ( 95 – 32 )

TC ₌ 5/9 ( 63 )

TC = _315/9

TC ₌ 35 ^o C

8. Raws li daim duab hauv qab no, txiav txim siab qhov kub P ntawm lub ntsuas kub Celsius.

tshuaj

T_C = 100/180 (T_F - 32)

TC ₌ 5/9 (TF _– 32)

TC = _5/9 (104 – 32)

TC ₌ 5/9 (72)

TC = _360/9

TC = 40 ^oC_​

9. Yog tias qhov kub ntawm Celsius nplai raws li qhia hauv daim duab hauv qab no, txiav txim siab qhov kub ntawm Fahrenheit nplai raws li qhia hauv daim duab hauv qab no.

Tshuaj:

T^oF = (180/100) T^oC + 32

ToF = (9/5) ^ToC + ³²

ToF = (9/5) 60 + ³²

ToF = (9) 12 ⁺ 32

ToF = 108 ⁺ 32

ToF = ¹⁴⁰

1. Hloov cov nplai kub
2. Kev nthuav dav ncaj
3. Kev nthuav dav ntawm thaj chaw
4. Kev nthuav dav ntawm ntim
5. Thaum tshav kub kub
6. Kev sib npaug ntawm cua sov
7. Cov cua sov tshwj xeeb thiab lub peev xwm cua sov
8. Kub latent, kub ntawm fusion, kub ntawm vaporization
9. Kev txuag hluav taws xob rau kev hloov pauv cua sov

nyeem ntxiv

1. Daim duab qhia txog lub zog (F) piv rau qhov ntev (x ) tau qhia nyob rau hauv daim duab hauv qab no. Nrhiav qhov tsis hloov pauv ntawm lub caij nplooj ntoos hlav!

tshuaj

Cov qauv ntawm Hooke txoj cai :

k = F / x

F = lub zog (Newton)

k = lub caij nplooj ntoos hlav tas li (Newton/'meter')

x = qhov kev hloov pauv ntawm qhov ntev (meters)

Caij nplooj ntoos hlav tas li:

k = 10 / 0.02 = 20 / 0.04

k = 500 N/m2

[irp]

2. Txheeb xyuas qhov tsis hloov pauv ntawm lub caij nplooj ntoos hlav.

tshuaj

Caij nplooj ntoos hlav tas li:

k = F / x

k = 5 / 0.01 = 10 / 0.02 = 15 / 0.03 = 20 / 0.04

k = 500 N/m2

[irp]

3. Lub Caij Nplooj Ntoos Hlav A muaj qhov ntev thawj zaug yog 60 cm thiab lub caij nplooj ntoos hlav B muaj qhov ntev thawj zaug yog 90 cm. Lub Caij Nplooj Ntoos Hlav A muaj qhov tas mus li 100 N/m, lub caij nplooj ntoos hlav B muaj qhov tas mus li 200 N/m. Qhov piv ntawm qhov kev hloov pauv ntawm qhov ntev ntawm lub caij nplooj ntoos hlav A rau qhov kev hloov pauv ntawm qhov ntev ntawm lub caij nplooj ntoos hlav B yog…

Paub:

Qhov tsis hloov ntawm lub caij nplooj ntoos hlav A (k _A ) = 100 N/m

Qhov tsis hloov ntawm lub caij nplooj ntoos hlav B (kB ₎ = 200 N/m

Lub zog ntawm lub caij nplooj ntoos hlav A (F _A ) = F

Lub zog ntawm lub caij nplooj ntoos hlav B (F _B ) = F

Xav tau: Δl _A : Δl _B

Tshuaj:

Cov qauv ntawm Hooke txoj cai:

Δl = F / k

Δl = qhov kev hloov pauv ntawm qhov ntev, F = lub zog, k = tas li

Qhov kev hloov pauv ntawm qhov ntev ntawm lub caij nplooj ntoos hlav A:

Δl _A = F _A / k _A = F / 100

Qhov kev hloov pauv ntawm qhov ntev ntawm lub caij nplooj ntoos hlav B:

Δl _B = F _B / k _B = F / 200

Qhov piv ntawm qhov kev hloov pauv ntawm qhov ntev ntawm lub caij nplooj ntoos hlav A rau qhov kev hloov pauv ntawm qhov ntev ntawm lub caij nplooj ntoos hlav B:

Δl _A : Δl _B

F/100 : F/200

1 / 100 : 1 / 200

1 / 1 : 1 / 2

2: 1

[irp]

4. Ib txoj hlua nylon uas ntev li qub yog 20 cm, raug rub los ntawm lub zog 10 N. Qhov kev hloov ntawm qhov ntev ntawm txoj hlua yog 2 cm. Txheeb xyuas qhov loj ntawm lub zog yog tias qhov kev hloov ntawm qhov ntev yog 6 cm.

Paub:

Lub zog (F) = 10 N

Qhov kev hloov pauv ntawm qhov ntev ( Δl ) = 2 cm = 0.02 m

Xav tau: qhov loj ntawm lub zog (F) yog tias Δl = 0.06 m.

Tshuaj:

Tsis tu ncua:

k = F / Δl

k = 10 / 0.02 = 500 N/m2

Qhov loj ntawm lub zog (F) yog tias Δl = 0.06 m:

F = kx

F = (500)(0.06)

F = 30 N

[irp]

[wpdm_package id='689′]

1. Txoj cai ntawm Hooke
2. Kev ntxhov siab, kev nyuaj siab, Young's modulus

nyeem ntxiv

Kev Nyuaj Siab ntawm Young's modulus - Teeb Meem thiab Kev Dais Teeb Meem

1. Ib txoj hlua nylon muaj txoj kab uas hla 2 hli, rub los ntawm lub zog ntawm 100 N. Txheeb xyuas qhov kev ntxhov siab!

Paub:

Lub zog (F) = 100 N

Txoj kab uas hla (d) = 2 hli = 0.002 m

Lub vojvoog (r) = 1 hli = 0.001 m

Xav tau: Kev ntxhov siab

Tshuaj:

Thaj Chaw:

^A = πr2

A = (3.14)(0.001 m) ² = 0.00000314 m ²

^A = 3.14 x 10 ^-6 m2

Kev ntxhov siab:

[irp]

2. Ib txoj hlua uas ntev li 100 cm thaum xub thawj raug rub los ntawm lub zog. Qhov hloov pauv ntawm qhov ntev ntawm txoj hlua yog 2 hli. Txheeb xyuas qhov kev ntxhov siab!

Paub:

Qhov ntev qub (l ₀ ) = 100 cm = 1 m

Qhov kev hloov pauv ntawm qhov ntev (Δl) = 2 hli = 0.002 m

Xav tau: Lub zog

Tshuaj:

Lub tsheb ciav hlau s:

[irp]

3. Ib txoj hlua uas muaj txoj kab uas hla 4 hli muaj qhov ntev thawj zaug yog 2 m. Txoj hlua raug rub los ntawm lub zog ntawm 200 N. Yog tias qhov ntev kawg ntawm lub caij nplooj ntoos hlav yog 2.02 m, txiav txim siab: (a) kev ntxhov siab (b) kev ntxhov siab (c) Young's modulus

Paub:

Txoj kab uas hla (d) = 4 hli = 0.004 m

Lub vojvoog (r) = 2 hli = 0.002 m

Luas A = π r ² = (3.14)(0.002 m) ²

^{Cheeb Tsam (} A) = 0.00001256 m2 ⁼ 12.56 x 10 ^-6 m2

Lub zog (F) = 200 N

Qhov ntev qub ntawm lub caij nplooj ntoos hlav (l ₀ ) = 2 m

Qhov kev hloov ntawm qhov ntev (Δl) = 2.02 – 2 = 0.02 m

Xav tau: (a) Kev ntxhov siab (b) Kev ntxhov siab c) Young's modulus

Tshuaj:

(a) Kev ntxhov siab

(b) Qhov Kev Nyuaj Siab

(c) Young's modulus

[irp]

4. Ib txoj hlua muaj txoj kab uas hla 1 cm thiab qhov ntev thawj yog 2 m. Lub zog ntawm 200 N rub txoj hlua. Txheeb xyuas qhov kev hloov pauv ntawm qhov ntev ntawm txoj hlua! Young's modulus ntawm txoj hlua = 5 x 10 ⁹ N/m ²

Paub:

Young's modulus (E) = 5 x 10 ⁹ N/ ^m2

Qhov ntev qub (l ₀ ) = 2 m

Lub zog (F) = 200 N

Txoj kab uas hla (d) = 1 cm = 0.01 m

Lub vojvoog (r) = 0.5 cm = 0.005 m = 5 x 10 ^-3 m

Cheeb Tsam ( A) = π r2 ⁼ (3.14)(5 x 10 ^-3 m) ² = (3.14)(25 x 10 ^-6 m2 ⁾

Cheeb Tsam ( ^A ) = 78.5 x 10 ^-6 m2 = 7.85 x 10 ^{-5 m2}

Xav tau : Qhov kev hloov pauv ntawm qhov ntev (Δl)

Tshuaj:

Cov qauv ntawm Young's modulus:

Qhov kev hloov ntawm qhov ntev :

[irp]

5. Ib lub pob zeb ua vaj tse muaj qhov siab ntawm 5 meters thiab muaj ib cheeb tsam ntawm 3 m ³ txhawb nqa qhov hnyav ntawm 30,000 kg. Txheeb xyuas (a) Qhov kev ntxhov siab (b) Qhov kev ntxhov siab (c) Qhov kev hloov pauv ntawm qhov siab! Kev nrawm vim yog lub ntiajteb txawj nqus (g) = 10 m / s ^2. Young's modulus ntawm pob zeb ua vaj tse = 20 x 10 ⁹ N / m ²

Paub:

Young's modulus ntawm cov pob zeb ua vaj tse = 20 x 10 ⁹ N/ ^m2

Qhov siab pib (l ₀ ) = 5 meters

Thaj chaw ntawm chav tsev (A) = 3 m ²

Qhov hnyav (w) = mg = (30,000)(10) = 300,000 N

Xav tau: (a) Kev ntxhov siab (b) Kev nyuaj siab (c) Kev hloov pauv ntawm qhov siab!

Tshuaj:

(a) Kev ntxhov siab

(b) Qhov Kev Nyuaj Siab

(c) Qhov kev hloov pauv ntawm qhov siab

[irp]

1. Txoj cai ntawm Hooke
2. Kev ntxhov siab, kev nyuaj siab, Young's modulus

nyeem ntxiv

1. Ib lub pob, uas txuas rau qhov kawg ntawm txoj hlua kab rov tav, tig mus rau hauv ib lub voj voog uas muaj radius 20 cm. Lub pob tig ib ncig ntawm 360 ^o txhua ob. Txheeb xyuas qhov loj ntawm qhov kev nrawm ntawm centripetal!

Paub:

Qhov ceev ntawm lub kaum sab xis (ω ) = 360 ^o / vib nas this = 1 revolution/ vib nas this = 6.28 radians/ vib nas this

Lub vojvoog (r) = 20 cm = 0.2 m

Xav tau: Centripetal acceleration (a _r )

Tshuaj:

ib _r = v ² / r —> v = r ω

a _r = (r ω) ² / r = r ² ω ² / r

ib _r = r ω ²

a _s = kev nrawm ntawm centripetal, v = linear velocity, r = radius, ω = angular velocity

Qhov loj ntawm centripetal acceleration :

a _r = r ω ² a _r = (0,2 m)( 6.28 rad/s)

ib _r = 1.256 m/ ^s2

[irp]

2. Lub log uas muaj 30 cm radius tig nrog lub zog 180 rpm. Txheeb xyuas qhov kev nrawm ntawm lub centripetal ntawm ib qho chaw ntawm ntug ntawm lub log!

Paub:

Lub vojvoog (r) = 30 cm = 0.3 m

Qhov ceev ntawm lub kaum sab xis ( ω ) = 180 lub voj voog / 60 vib nas this = 3 lub voj voog / vib nas this = (3) (6.28 radians) / vib nas this = 18.84 radians / vib nas this

Xav tau: kev nrawm ntawm centripetal ( a _r ) ntawm r = 0.3 m

Tshuaj:

Qhov loj ntawm centripetal acceleration:

ib _r = r ω ²

ib _r = (0.3 m)(18.84 rad/s)

ib _r = 5.65 m/ ^s2

3. Lub tsheb sib tw khiav ntawm txoj kev voj voog uas muaj vojvoog 50 meters. Yog tias lub tsheb khiav ceev 72 km/h, txiav txim siab qhov loj ntawm qhov kev nrawm ntawm lub centripetal!

Paub:

Lub vojvoog (r) = 50 meters

Ceev (v) = 72 km/h = (72)(1000 meters) / 3600 vib nas this = 20 meters/ vib nas this

Xav tau : qhov loj ntawm qhov kev nrawm ntawm centripetal (a _r )

Tshuaj:

a _r = v ² / r = 20 ² / 50 = 400 / 50 = 8 m/s ²

[irp]

4. Lub tsheb muaj qhov siab tshaj plaws ntawm centripetal acceleration ntawm 10 m/s ² , yog li lub tsheb tuaj yeem tig tau yam tsis plam tawm ntawm txoj kev nkhaus. Yog tias lub tsheb txav mus los ntawm qhov ceev tas li 108 km/h, qhov radius ntawm qhov nkhaus unbanked yog dab tsi?

Paub:

Kev nrawm ntawm lub zog centripetal (a _r ) = 10 m/s ²

Lub tsheb ceev (v) = 108 km/ h = (108)(1000) / 3600 = 30 meters s /se c rau d

Xav tau: radius (r)

Tshuaj:

r = v ² / a _r

r = 30 ² / 10 = 900 / 10 = 90 meters s

[irp]

[wpdm_package id='433′]

[wpdm_package id='439′]

1. Kev hloov pauv cov chav ntawm lub kaum sab xis piv txwv cov teeb meem nrog cov kev daws teeb meem
2. Cov teeb meem thiab kev daws teeb meem ntawm cov qauv angular displacement thiab linear displacement
3. Cov teeb meem piv txwv ntawm angular velocity thiab linear velocity nrog cov kev daws teeb meem
4. Cov teeb meem piv txwv ntawm kev nrawm nrawm thiab kev nrawm nrawm linear nrog cov kev daws teeb meem
5. Cov teeb meem piv txwv ntawm kev txav mus los sib npaug nrog cov kev daws teeb meem
6. Cov teeb meem ntawm cov qauv centripetal acceleration nrog cov kev daws teeb meem
7. Cov teeb meem piv txwv ntawm kev txav mus los tsis sib xws nrog cov kev daws teeb meem

nyeem ntxiv

1. Ib lub log uas muaj 3 0 cm hauv lub vojvoog tig ntawm qhov tsis hloov pauv 5 rad/s ^2. Qhov loj ntawm qhov kev nrawm ntawm ib qho chaw nyob ntawm (a) 10 cm ntawm qhov chaw nruab nrab (b) 20 cm ntawm qhov chaw nruab nrab (c) ntawm ntug ntawm lub log yog dab tsi?

Paub:

Lub vojvoog (r) = 30 cm = 0.3 m

Kev nrawm ntawm lub kaum sab xis ( α ) = 5 rad/s ²

Xav tau: kev nrawm linear (a) r = 0.1 m (b) r = 0.2 m (c) r = 0.3 m

Tshuaj:

Kev sib raug zoo ntawm kev nrawm linear (a) thiab kev nrawm angular:

a = r α

(a) kev nrawm nrawm, r = 0.1 m

a = (0.1 m)(5 rad/s2 ⁾ = 0.5 m/ ^s2

(b) kev nrawm nrawm, r = 0.2 m

a = (0.2 m)(5 rad/s2 ⁾ = 1 m/ ^s2

(c) kev nrawm nrawm, r = 0.3 m

a = (0.3 m)(5 rad/s2 ⁾ = 1.5 m/ ^s2

[irp]

2. Ib lub pulley uas muaj lub vojvoog 50 cm. Yog tias qhov kev nrawm ntawm ib qho chaw nyob ntawm ntug ntawm lub pulley yog 2 m/s ² , txiav txim siab qhov kev nrawm ntawm lub pulley!

Paub:

Lub vojvoog (r) = 50 cm = 0,5 m

kev nrawm nrawm (a) = 2 m/s ²

Xav tau: qhov kev nrawm ntawm lub kaum sab xis

Tshuaj:

α = a / r = 2 / 0.5 = 4 rad/s ²

3. Cov hniav hauv lub tshuab sib tov muaj 20 cm hauv lub vojvoog, thaum pib so. Tom qab 2 vib nas this, cov hniav tig 10 rad/s. Txheeb xyuas qhov loj ntawm kev nrawm linear (a) ib qho chaw nyob ntawm 10 cm ntawm qhov chaw nruab nrab (b) ib qho chaw nyob ntawm ntug ntawm cov hniav.

Paub:

Lub vojvoog (r) = 20 cm = 0.2 m

_{Qhov pib ntawm lub kaum sab xis} ( ωo ) = 0

Qhov kawg angular velocity ( ω _{t )} = 10 radians/ob

Lub sijhawm luv (t) = 2 vib nas this

Xav tau: qhov kev nrawm linear ntawm ib qho chaw nyob ntawm (a) r = 0.1 m (b) r = 0.2 m

Tshuaj:

ω _t = ω _o + α t

10 = 0 + α (2)

10 = 2 α

α = 10 / 2

 α = 5 rad/s

(a) kev nrawm nrawm ntawm r = 0.1 m

a = r α = (0.1 m)(5 rad/s ² ) = 0.5 m/s ²

(b) kev nrawm nrawm ntawm r = 0.2 m

a = r α = (0.2 m)(5 rad/s ² ) = 1 m/s ²

[irp]

4. Ib lub log uas muaj 20 cm radius raug nrawm rau 2 vib nas this los ntawm 20 rad/s kom so. Txheeb xyuas qhov loj ntawm kev nrawm linear (a) ib qho chaw nyob ntawm 10 cm ntawm qhov chaw nruab nrab (b) ib qho chaw nyob ntawm 10 cm ntawm qhov chaw nruab nrab.

Paub:

Lub vojvoog (r) = 20 cm = 0.2 m

Qhov pib ceev ntawm lub kaum sab xis ( ωo) = ₂₀ rad/s

_{Qhov ceev kawg ntawm lub kaum sab xis} ( ωt ) = 0

Lub sijhawm luv (t) = 2 vib nas this

Xav tau: Qhov kev nrawm linear (a) r = 0.1 m (b) r = 0.2 m

Tshuaj:

ω _t = ω _o + α t

0 = 20 + α (2)

-20 = 2 α

α = -20 / 2

 α = -10 rad/s

Lub cim tsis zoo txhais tau tias qhov ceev ntawm lub kaum sab xis txo qis.

(a) kev nrawm nrawm ntawm r = 0.1 m

a = r α = (0.1 m)(-10 rad/s ² ) = -1 m/s ²

(b) kev nrawm nrawm ntawm r = 0.2 m

a = r α = (0.2 m)(-10 rad/s ² ) = -2 m/s ²

[irp]

[wpdm_package id='429′]

[wpdm_package id='439′]

1. Kev hloov pauv cov chav ntawm lub kaum sab xis piv txwv cov teeb meem nrog cov kev daws teeb meem
2. Cov teeb meem thiab kev daws teeb meem ntawm cov qauv angular displacement thiab linear displacement
3. Cov teeb meem piv txwv ntawm angular velocity thiab linear velocity nrog cov kev daws teeb meem
4. Cov teeb meem piv txwv ntawm kev nrawm nrawm thiab kev nrawm nrawm linear nrog cov kev daws teeb meem
5. Cov teeb meem piv txwv ntawm kev txav mus los sib npaug nrog cov kev daws teeb meem
6. Cov teeb meem ntawm cov qauv centripetal acceleration nrog cov kev daws teeb meem
7. Cov teeb meem piv txwv ntawm kev txav mus los tsis sib xws nrog cov kev daws teeb meem

nyeem ntxiv

1. Ib lub pob nyob rau ntawm qhov kawg ntawm ib txoj hlua tig ib yam nkaus hauv ib lub voj voog kab rov tav ntawm lub voj voog radius 2 meters ntawm qhov ceev ntawm lub kaum sab xis tas li 10 rad/s. Txheeb xyuas qhov loj ntawm qhov ceev ntawm kab ncaj ntawm ib qho chaw nyob:

(a) 0.5 meters ntawm qhov chaw nruab nrab

(b) 1 meter ntawm qhov chaw nruab nrab

(c) 2 meters ntawm qhov chaw nruab nrab

Paub:

Lub vojvoog (r) = 0.5 meters s, 1 meters, 3 meters

Qhov ceev ntawm lub kaum sab xis = 10 radians s / se cond

Xav tau: linear velocity

Tshuaj:

v = r ω

v = qhov ceev ntawm kab , r = radius , ω = qhov ceev ntawm lub kaum sab xis

(a) Qhov ceev linear (v) ntawm ib qho chaw nyob ntawm r = 0.5 meters

v = r ω = (0.5 meters s )(10 rad/s) = 5 meters s /se cond

(b) Qhov ceev linear (v) ntawm ib qho chaw nyob ntawm r = 1 meter

v = r ω = (1 meter)(10 rad/s) = 10 meters s /se cond

(c) Qhov ceev linear (v) ntawm ib qho chaw nyob ntawm r = 2 meters s

v = r ω = (2 meters s )(10 rad/s) = 20 meters s /se cond

[irp]

2. Cov hniav hauv lub tshuab sib tov tig ntawm tus nqi ntawm 5000 rpm. Txheeb xyuas qhov loj ntawm qhov ceev linear:

(a) ib qho chaw nyob 5 cm ntawm qhov chaw nruab nrab

(b) ib qho chaw nyob 10 cm ntawm qhov chaw nruab nrab

Paub:

Lub vojvoog (r) = 5 cm thiab 10 cm

Qhov ceev ntawm lub kaum sab xis (ω) = 5000 kho sawv daws / 60 vib nas thisob peb = 83.3 kho sawv daws / semob = (83.3)(6.28 radians) / semob = 523.3 radians / semob

Xav tau: Qhov loj ntawm qhov ceev linear

Tshuaj:

(a) Qhov loj ntawm qhov ceev ntawm ib qho chaw nyob 0.05 m ntawm qhov chaw nruab nrab

v = r ω = (0.05 m)( 523.3 rad/s) = 26 m/s

(b) Qhov loj ntawm qhov ceev ntawm ib qho chaw nyob 0,1 m ntawm qhov chaw nruab nrab

v = r ω = (0.1 m)( 523.3 rad/s) = 52 m/s

3. Ib lub taw tes ntawm ntug ntawm lub log uas muaj 30 cm hauv lub vojvoog, ncig ib lub voj voog ntawm qhov ceev tas li 10 meters/ib pliag.

Qhov loj ntawm qhov ceev ntawm lub kaum sab xis yog dab tsi?

Paub:

Lub vojvoog ( r) = 30 cm = 0.3 meters s

Qhov ceev linear (v) = 10 meters s / se cond

Xav tau: qhov ceev ntawm lub kaum sab xis

Tshuaj:

ω = v / r = 10 / 0.3 = 33 radians s /se cond

[irp]

4. Lub tsheb uas muaj log tsheb loj li 50 cm, khiav tau 10 meters hauv 1 vib nas this. Lub kaum sab xis ceev npaum li cas?

Paub:

Lub vojvoog (r) = 0.25 meters

Qhov ceev ntawm ib qho taw tes ntawm ntug ntawm lub log tsheb (v) = 10 meters s / se cond

Xav tau: Qhov ceev ntawm lub kaum sab xis

Tshuaj:

ω = v / r = 10 / 0.25 = 40 radians s /se cond

5. Lub kaum sab xis ntawm lub log 20 cm hauv radians yog 120 rpm. Yog tias lub tsheb mus ncig hauv 10 vib nas this, qhov deb yog dab tsi.

Paub:

Lub vojvoog (r) = 20 cm = 0.2 meter s

Qhov ceev ntawm lub kaum sab xis = 120 rev / 60 setej yam kev mob = 2 rev / semob = (2)(6.28) radians / semob = 12.56 radians / semob

Xav tau: qhov deb

Tshuaj:

Qhov ceev ntawm ntug ntawm lub log:

v = r ω = (0.2 meter s )(12.56 radians s /se cond ) = 2.5 meters s /se cond

2.5 'meter's / second txhais tau tias yog ib qho chaw nyob ntawm ntug ntawm lub log mus ncig 2.5 'meter's txhua 1 vib nas this. Tom qab 10tej yam kev mob, lub ntsiab lus mus ncig 25 'meter's.

Yog li ntawd, qhov deb yog 25 meters.

[irp]

[wpdm_package id='427′]

[wpdm_package id='439′]

1. Kev hloov pauv cov chav ntawm lub kaum sab xis piv txwv cov teeb meem nrog cov kev daws teeb meem
2. Cov teeb meem thiab kev daws teeb meem ntawm cov qauv angular displacement thiab linear displacement
3. Cov teeb meem piv txwv ntawm angular velocity thiab linear velocity nrog cov kev daws teeb meem
4. Cov teeb meem piv txwv ntawm kev nrawm nrawm thiab kev nrawm nrawm linear nrog cov kev daws teeb meem
5. Cov teeb meem piv txwv ntawm kev txav mus los sib npaug nrog cov kev daws teeb meem
6. Cov teeb meem ntawm cov qauv centripetal acceleration nrog cov kev daws teeb meem
7. Cov teeb meem piv txwv ntawm kev txav mus los tsis sib xws nrog cov kev daws teeb meem

nyeem ntxiv

Hloov cov chav ntawm lub kaum sab xis (degree, radian, revolution)

1. ¼ rev = ….. ^o ( degree ) ?

tshuaj

1 lub voj voog = 360 ^o

½ rev = 180 ^o

¼ tig = 90 ^o

2. ½ rev = ……. r ad?

tshuaj

1 rev = 2 π rad = 2(3.14) rad = 6.28 rad

½ rev = pi rad = 3.14 rad

3. 180 ^o = ….. rev ?

tshuaj

360 ^o = 1 lub voj voog

180 ^o = ½ rev

[irp]

4. 90 ^o = ….. rad ?

tshuaj

360 ^AWG = 2.28 BTC​

180 ^o = π rad = 3.14 rad

90 ^o = ½ π rad = ½ (3.14) = 1.57

5. 60 rad = ….. rev?

tshuaj

6.28 rad = 1 rev

60 rad/6.28 = 9.55 rev

6. 40 rad= ….. ^o?

tshuaj

6.28 rad = 360 ^o

40 rad/6.28 = (6.37)(360 ^o ) = 2292.99 ^o

[irp]

Kev hloov pauv ntawm lub kaum sab xis thiab kev hloov pauv ntawm txoj kab ncaj

1. Lub log tsheb kauj vab uas muaj txoj kab uas hla 60 cm tig tau 10 radians. Qhov kev hloov pauv ntawm ib qho ntawm ntug ntawm lub log yog dab tsi?

Paub:

Lub vojvoog (r) = 30 cm = 0.3 m

Lub kaum sab xis (θ ) = 10 radians

Xav tau: linear displacement (l)

Tshuaj:

l = rθ

l = (0.3 m)(10 rad)

l = 3 meters

2. Lub log uas muaj 50 cm radius tig tau 360 ^o . Qhov kev hloov chaw ntawm ib qho taw tes ntawm ntug ntawm lub log yog dab tsi?

Paub:

Lub vojvoog (r) = 50 cm = 0.5 meters

Lub kaum sab xis ( θ ) = 360 ^o = 6.28 radians

Xav tau: linear displacement (l)

Tshuaj:

l = rθ

l = (0.5 m)(6.28 rad)

l = 3.14 meters

[irp]

3. Lub log uas muaj lub vojvoog 50 cm tig tau 2 zaug. Qhov kev hloov pauv ntawm ib qho chaw ntawm ntug ntawm lub log yog dab tsi?

Paub:

Lub vojvoog (r) = 50 cm = 0,5 m

Lub kaum sab xis ( θ ) = 2 lub voj voog = (2)(6.28 radians) = 12.56 radians

Xav tau: linear displacement (l)?

Tshuaj:

l = rθ

l = (0.5 m)(12.56 rad)

l = 6.28 m

4. Ib qho chaw ntawm ntug ntawm lub log uas muaj 2 meters hauv lub vojvoog, txav mus 100 meters. Txheeb xyuas qhov kev hloov pauv ntawm lub kaum sab xis.

Paub:

Lub vojvoog (r) = ½ (txoj kab uas hla) = ½ (2 meters) = 1 'meter'

Kev hloov pauv kab ncaj (l) = 100 meters

Tshuaj:

(a) Kev hloov pauv ntawm lub kaum sab xis (hauv radians)

θ = s / r = 100 / 1 = 100 radians

(b) Kev hloov pauv ntawm lub kaum sab xis (hauv degrees)

1 radian = 360 ^o

100 radians = 100(360 ^o ) = 36,000 radians

(c) Kev hloov pauv ntawm lub kaum sab xis (hauv kev tig ib ncig)

6.28 radians = 1 revolution

36,000 / 6.28 = 5732,484 lub voj voog

[irp]

5. Ib lub khoom me me puag ncig ib lub voj voog 10 meters thiab tig 180 ^o . Lub radius yog dab tsi?

Paub:

Kev hloov pauv kab (l) = 10 meters

Lub kaum sab xis ( θ ) = 180 ^o = 3.14 radians

Xav tau: radius (r)

Tshuaj:

r = l / θ = 10 / 3.14 = 3.18 m

[irp]

1. Kev hloov pauv cov chav ntawm lub kaum sab xis piv txwv cov teeb meem nrog cov kev daws teeb meem
2. Cov teeb meem thiab kev daws teeb meem ntawm cov qauv angular displacement thiab linear displacement
3. Cov teeb meem piv txwv ntawm angular velocity thiab linear velocity nrog cov kev daws teeb meem
4. Cov teeb meem piv txwv ntawm kev nrawm nrawm thiab kev nrawm nrawm linear nrog cov kev daws teeb meem
5. Cov teeb meem piv txwv ntawm kev txav mus los sib npaug nrog cov kev daws teeb meem
6. Cov teeb meem ntawm cov qauv centripetal acceleration nrog cov kev daws teeb meem
7. Cov teeb meem piv txwv ntawm kev txav mus los tsis sib xws nrog cov kev daws teeb meem

nyeem ntxiv

1. Ib lub log uas muaj 1 'meter' radius nrawm nrawm sib npaug zos ntawm 2 rad/s ^2. Txheeb xyuas qhov nrawm ntawm lub kaum sab xis thiab qhov ceev ntawm lub kaum sab xis ntawm lub log, 2 vib nas this tom qab.

Paub:

Lub vojvoog (r) = 1 'meter'

Kev nrawm ntawm lub kaum sab xis (α ) = 2 rad/s ²

Xav tau: kev nrawm ntawm lub kaum sab xis thiab qhov ceev ntawm lub kaum sab xis tom qab 2 vib nas this.

Tshuaj:

(a) Kev nrawm nrawm ntawm lub kaum sab xis hauv 2 vib nas this

Qhov kev nrawm ntawm lub kaum sab xis yog qhov tsis hloov pauv, yog li tom qab 2 vib nas this, qhov kev nrawm ntawm lub log yog 2 rad/s ².

(b) Qhov ceev ntawm lub kaum sab xis hauv 2 vib nas this

Kev nrawm ntawm lub kaum sab xis 2 rad/s ² txhais tau tias qhov ceev ntawm lub kaum sab xis nce 2 radians/ob txhua 1 ob. Tom qab 1 ob, qhov ceev ntawm lub kaum sab xis = 2 radians/ob. Tom qab 2 ob, qhov ceev ntawm lub kaum sab xis = 4 radians/ob.

[irp]

2. Ib lub khoom me me nrawm nrawm sib npaug zos thaum nws so mus txog 60 rpm hauv 10 vib nas this. Txheeb xyuas qhov loj ntawm qhov nrawm ntawm lub kaum sab xis!

Paub:

Qhov pib ntawm lub kaum sab xis (ω _o ) = 0

Qhov kawg angular velocity ( ω _t ) = 60 rpm = 60 revolutions / 60 vib nas this = 1 revolutions / vib nas this = 6,28 radians / vib nas this

Lub sijhawm luv (t) = 10 vib nas this

Xav tau: Kev nrawm ntawm lub kaum sab xis ( α )

Tshuaj:

ω _o = qhov pib ntawm lub kaum sab xis, ω _t = qhov kawg ntawm lub kaum sab xis, α = qhov kev nrawm ntawm lub kaum sab xis, t = lub sijhawm luv, θ = lub kaum sab xis.

ω _t = ω _o + α t

6.28 = 0 + α (10)

6.28 = 10 α

α = 6.28 / 10

α = 0.628 rad/ ^s2

Qhov loj ntawm qhov kev nrawm ntawm lub kaum sab xis = 0.628 rad/ ^s2

3. Ib yam khoom qeeb qeeb ntawm 20 rad/s mus rau 10 rad/s hauv 4 vib nas this. Txheeb xyuas qhov loj ntawm qhov kev nrawm ntawm lub kaum sab xis!

Paub:

Lub sijhawm luv (t) = 4 vib nas this

Qhov pib ntawm lub kaum sab xis ( ωo ₎ = 20 rad/s

Qhov kawg ntawm lub kaum sab xis ( ω _t ) = 10 rad/s

Xav tau : qhov loj ntawm qhov kev nrawm ntawm lub kaum sab xis (α )

Tshuaj:

ω _t = ω _o + α t

10 = 20 + α (4)

10 – 20 = 4 α

-10 = 4 α

α = -10 / 4

α = – 2.5 rad/ ^s2

Qhov loj ntawm qhov kev nrawm ntawm lub kaum sab xis yog -2.5 rad/s2 ^. Lub cim tsis zoo txhais tau tias yam khoom tab tom qeeb qeeb. Kev nrawm = qhov ceev ntawm lub kaum sab xis nce ntxiv, kev qeeb qeeb = qhov ceev ntawm lub kaum sab xis txo qis.

[irp]

4. Ib yam khoom raug nrawm rau 2 vib nas this los ntawm 10 rad/s mus rau 2 rad/s ^2. Txheeb xyuas lub kaum sab xis uas lub khoom puag ncig!

Paub:

qhov pib ntawm lub kaum sab xis ( ω _o ) = 10 rad/s

qhov kev nrawm ntawm lub kaum sab xis (α ) = 2 rad/s ²

lub sijhawm luv (t) = 2 vib nas this

Xav tau: lub kaum sab xis (θ)

Tshuaj:

θ = ωo ₊ ½ α t ²

θ = (10)(2) + ½ (2)(2 ² )

θ = 20 + (1)(4) = 20 + 4

θ = 24 radians

5. Lub log tsheb qeeb qeeb los ntawm 20 rad/s mus rau so tom qab ncig 20 radians. Txheeb xyuas qhov loj ntawm qhov kev nrawm ntawm lub kaum sab xis ntawm lub log!

Paub:

qhov pib ceev ntawm lub kaum sab xis ( ω _o ) = 20 rad/s

_{qhov ceev kawg ntawm lub kaum sab xis} ( ωt ) = 0

Lub kaum sab xis ( θ ) = 20 radians

Xav tau: qhov loj ntawm qhov kev nrawm ntawm lub kaum sab xis (α )

Tshuaj:

ω _t ² = ω _o ² + 2 α θ

0 = 20 ² + 2 α (20)

0 = 400 + 40 α

400 = – 40 α

α = – 400 / 40

α = – 10 rad/ ^s2

6. Ib tug pas nrig PQ uas ntev 60 cm tig ib ncig ntawm qhov chaw Q ua lub axis ntawm kev tig thiab PQ ua lub vojvoog ntawm lub voj voog. Tus pas nrig PQ nrawm los ntawm so mus rau 0.3 rad/s ^2. Qhov ceev ntawm qhov chaw P ntawm t = 10 vib nas this yog dab tsi, yog tias qhov chaw pib ntawm lub kaum sab xis yog 0.

Paub:

Qhov ntev ntawm tus pas nrig PQ = lub vojvoog ntawm lub vojvoog (r) = 60 cm = 60/100 m = 0.60 m

Qhov pib ceev ntawm lub kaum sab xis (ωo ₎ = 0 rad/s

Kev nrawm ntawm lub kaum sab xis (α) = 0.3 rad s ^-2

Qhov pib ntawm lub kaum sab xis (θ _o ) = 0

Xav tau: Qhov ceev linear (v) ntawm qhov chaw P ntawm t = 10 vib nas this

Tshuaj:

Qhov ceev kawg ntawm lub kaum sab xis tom qab 10 vib nas this:

ω _t = ω _o + α t = 0 rad/s + (0.3 rad s ^-2 )(10 s) = 3 rad/s

Qhov kawg linear ceev tom qab 10 vib nas this:

v = r ω = (0.6 m)(3 rad/s) = 1.8 m/s

[irp]

7. Ib yam khoom tig nrog qhov ceev pib ntawm 4 rad/s thiab qhov kev nrawm ntawm lub kaum sab xis yog 0.5 rad/s ^2. Qhov ceev ntawm yam khoom tom qab 4 vib nas this yog dab tsi.

Paub:

Qhov pib ceev ntawm lub kaum sab xis (ωo ₎ = 4 rad/s

Kev nrawm ntawm lub kaum sab xis (α) = 0.5 rad/s ²

Lub sijhawm luv (t) = 4 vib nas this

Xav tau: Qhov ceev ntawm yam khoom tom qab 4 vib nas this (ω _t )

Tshuaj:

ω _t = ω _o + α t

ω _t = 4 + (0.5)(4)

ω _t = 4 + 2

ω _t = 6 rad/s

8. Lub moos phab ntsa uas muaj txoj kab uas hla 10 cm muaj peb lub koob, txhua lub los qhia cov teev, feeb thiab vib nas this. Kev sib piv ntawm tus naj npawb ntawm cov voj voog ntawm lub koob teev: lub koob feeb: lub koob thib ob.

A. 1: 3: 180

B. 1: 12: 720

C. 4: 12: 180

D. 4: 12: 720

Paub:

1 teev = 60 feeb

12 teev = (12) (60 feeb) = 720 feeb

Qhov ceev ntawm lub koob teev = 1 lub voj voog / 12 teev = 1 lub voj voog / 720 feeb

Qhov ceev ntawm lub koob feeb = 1 tig / 1 teev = 1 tig / 60 feeb

Qhov ceev ntawm lub koob thib ob = 1 revolution / 1 feeb

Xav tau: Kev sib piv ntawm tus naj npawb ntawm cov voj voog ntawm lub koob teev: lub koob feeb: lub koob thib ob

Tshuaj:

Qhov sib npaug ntawm kev txav mus los ncig:

Qhov ceev ntawm lub kaum sab xis = tus naj npawb ntawm kev hloov pauv / lub sijhawm sib nrug

Tus naj npawb ntawm kev tig = qhov ceev ntawm lub kaum sab xis x lub sijhawm sib nrug

Hauv tib lub sijhawm, piv txwv li, 1 feeb, muaj pes tsawg lub voj voog ntawm lub koob teev, koob feeb, thiab koob thib ob.

Tus naj npawb ntawm kev tig ntawm lub koob teev = qhov ceev ntawm lub kaum sab xis x lub sijhawm = (1 kev tig / 720 feeb) (1 feeb) = 1/720 kev tig

Tus naj npawb ntawm kev tig ntawm lub koob feeb = qhov ceev ntawm lub kaum sab xis x lub sijhawm = (1 kev tig / 60 feeb) (1 feeb) = 1/60 kev tig

Tus naj npawb ntawm kev tig ntawm lub koob thib ob = qhov ceev ntawm lub kaum sab xis x lub sijhawm = (1 kev tig / 1 feeb) (1 feeb) = 1/1 kev tig

Kev sib piv ntawm ntau qhov kev hloov pauv:

Tus naj npawb ntawm kev tig ntawm lub koob teev: tus naj npawb ntawm kev tig ntawm lub koob feeb: tus naj npawb ntawm kev tig ntawm lub koob thib ob.

1/720 : 1/60 : 1/1

1/720 : 12/720 : 720/720

1: 12: 720

Cov lus teb yog B.

9. Ib lub pob khi nrog ib txoj hlua. Lub pob tig kom nws txav mus rau hauv ib lub voj voog sib luag rau saum npoo ntawm lub ntiaj teb. Hauv qhov kev txav no, lub pob nrawm dua vim tias…..

A. Kev sib txhuam ntawm huab cua

B. Qhov hnyav ntawm lub pob

C. Lub zog nruj

D. Lub zog ntawm lub ntiajteb txawj nqus

Tshuaj:

Txoj cai thib ob ntawm Newton hais tias ib yam khoom raug nrawm yog tias muaj lub zog tshwm sim. Lub pob txuas nrog txoj hlua thiab thaum txoj hlua tig, lub pob kuj tig. Thaum lub pob tig (lub pob txav mus rau hauv lub voj voog), lub pob dhau los ntawm kev nrawm ntawm centripetal. Tag nrho cov khoom txav mus los yog kev nrawm ntawm centripetal ncig. Kev nrawm ntawm centripetal yog tshwm sim los ntawm lub zog centripetal . Lub zog centripetal rau qhov no yog lub zog nruj.

Cov lus teb yog C.

[irp]

[wpdm_package id='437′]

[wpdm_package id='439′]

1. Kev hloov pauv cov chav ntawm lub kaum sab xis piv txwv cov teeb meem nrog cov kev daws teeb meem
2. Cov teeb meem thiab kev daws teeb meem ntawm cov qauv angular displacement thiab linear displacement
3. Cov teeb meem piv txwv ntawm angular velocity thiab linear velocity nrog cov kev daws teeb meem
4. Cov teeb meem piv txwv ntawm kev nrawm nrawm thiab kev nrawm nrawm linear nrog cov kev daws teeb meem
5. Cov teeb meem piv txwv ntawm kev txav mus los sib npaug nrog cov kev daws teeb meem
6. Cov teeb meem ntawm cov qauv centripetal acceleration nrog cov kev daws teeb meem
7. Cov teeb meem piv txwv ntawm kev txav mus los tsis sib xws nrog cov kev daws teeb meem

nyeem ntxiv

1. Ib yam khoom txav mus los hauv ib lub voj voog nrog qhov ceev ntawm lub kaum sab xis tas li ntawm 10 rad/s. Txheeb xyuas (a) Qhov ceev ntawm lub kaum sab xis tom qab 10 vib nas this (b) Qhov kev hloov chaw ntawm lub kaum sab xis tom qab 10 vib nas this.

Paub:

Qhov ceev ntawm lub kaum sab xis (ω) = 10 rad/s

Xav tau:

(a) Qhov ceev ntawm lub kaum sab xis (ω) tom qab 10 vib nas this.

(b) Lub kaum sab xis (θ) tom qab 10 vib nas this

Tshuaj:

(a) Qhov ceev ntawm lub kaum sab xis (ω) tom qab 10 vib nas this

Khoom txav mus los ib ncig zoo li qub kom qhov ceev ntawm lub kaum sab xis tsis hloov pauv, 10 rad/s.

(b) Kev hloov chaw ntawm lub kaum sab xis (θ)

Qhov ceev ntawm lub kaum sab xis tas li 10 radians/ob txhais tau tias yam khoom nyob ib ncig ntawm 10 radians ib ob. Tom qab 10 vib nas this, yam khoom nyob ib ncig ntawm 10 x 10 radians = 100 radians.

[irp]

2. Ib lub khoom me me txav mus los hauv ib lub voj voog nrog qhov ceev tas li ntawm 10 m/s. Lub voj voog = 1 meter. Txheeb xyuas (a) Qhov ceev ntawm lub khoom me me tom qab 5 vib nas this (b) Qhov kev hloov chaw ntawm lub khoom me me tom qab 5 vib nas this (c) Kev nrawm ntawm lub centripetal.

Paub:

Lub vojvoog ntawm lub voj voog (r) = 1 'meter'

Qhov ceev ntawm cov khoom me me (v) = 10 m/s

Tshuaj:

(a) Qhov ceev ntawm cov khoom me me tom qab 5 vib nas this

Qhov kev txav ntawm cov khoom yog nyob rau hauv lub voj voog sib npaug zos kom qhov ceev yog tas li, 10 m / s.

(b) Qhov kev hloov pauv ntawm cov khoom me me tom qab 5 vib nas this

10 meters/ob txhais tau tias txhua 1 ob, qhov kev hloov pauv ntawm cov khoom me me = 10 meters. Tom qab 5 vib nas this, qhov kev hloov pauv ntawm cov khoom me me = 5 x 10 meters = 50 meters.

(c) Kev nrawm ntawm lub centripetal (a _r )

a _r = v ² / r = 10 ² / 1 = 100 / 1 = 100 m/s ²

3. Ib lub pob uas txuas rau ib kawg ntawm txoj hlua, tig mus rau hauv ib lub voj voog uas muaj lub vojvoog ntawm 2 meters ntawm qhov ceev tas li ntawm 60 rpm. Txheeb xyuas (a) qhov loj ntawm qhov ceev ntawm lub kaum sab xis tom qab 2 vib nas this (b) qhov kev hloov pauv ntawm lub kaum sab xis tom qab 1 feeb.

Paub:

Lub vojvoog vojvoog (r) = 2 meters

Kev ceev ntawm lub kaum sab xis (ω) = 60 rpm = 60 revolutions / 1 feeb

= 60 lub voj voog / 60 vib nas this = 1 lub voj voog / vib nas this = 2π radians / vib nas this

= 2(3.14) radians / vib nas this = 6.28 radians / vib nas this

Tshuaj:

(a) Qhov ceev ntawm lub kaum sab xis (ω) tom qab 2 vib nas this

Qhov ceev ntawm lub kaum sab xis yog qhov tsis hloov pauv yog li tom qab 2 vib nas this, qhov ceev ntawm lub kaum sab xis (ω) = 6.28 radians / vib nas this

(b) Kev hloov chaw ntawm lub kaum sab xis (θ)

Qhov ceev ntawm lub kaum sab xis = 1 tig/ob txhais tau tias txhua 1 ob, lub pob muaj 1 tig. Tom qab 60 vib nas this, lub pob txav 60 tig.

Qhov ceev ntawm lub kaum sab xis = 6.28 radians/ob txhais tau tias txhua 1 ob, lub pob txav nrog lub kaum sab xis ntawm 6.28 radians. Tom qab 60 vib nas this, lub pob txav 376.8 radians.

[irp]

4. Lub log tsheb kauj vab tig 120 zaug hauv 60 vib nas this. Qhov ceev ntawm lub kaum sab xis yog dab tsi?

Tshuaj:

(a) kev hloov pauv ib feeb (rpm)

120 lub voj voog / 60 vib nas this = 120 lub voj voog / 1 feeb = 120 lub voj voog / feeb = 120 rpm

(b) degrees ib ob ( ^o /s)

1 lub voj voog = 360 ^o , 120 lub voj voog = 43200 ^o

120 tig / 60 vib nas this = (120)(360 ^o ) / 60 vib nas this = 43200 ^o / 60 vib nas this = 720 ^o / vib nas this

(c) radians ib ob (rad/s)

1 kev hloov pauv = 6.28 radians

120 tig / 60 vib nas this = (120)(6.28) radians / 60 vib nas this = 753.6 radians / 60 vib nas this = 12.56 radians/ob vib nas this.

[irp]

[wpdm_package id='432′]

[wpdm_package id='439′]

1. Kev hloov pauv cov chav ntawm lub kaum sab xis piv txwv cov teeb meem nrog cov kev daws teeb meem
2. Cov teeb meem thiab kev daws teeb meem ntawm cov qauv angular displacement thiab linear displacement
3. Cov teeb meem piv txwv ntawm angular velocity thiab linear velocity nrog cov kev daws teeb meem
4. Cov teeb meem piv txwv ntawm kev nrawm nrawm thiab kev nrawm nrawm linear nrog cov kev daws teeb meem
5. Cov teeb meem piv txwv ntawm kev txav mus los sib npaug nrog cov kev daws teeb meem
6. Cov teeb meem ntawm cov qauv centripetal acceleration nrog cov kev daws teeb meem
7. Cov teeb meem piv txwv ntawm kev txav mus los tsis sib xws nrog cov kev daws teeb meem

nyeem ntxiv

1. Ib lub pob 0.1- kg, txuas rau qhov kawg ntawm txoj hlua kab rov tav, tig mus rau hauv ib lub voj voog uas muaj radius 50 cm thiab lub pob qhov ceev yog s 4 rad s ^-1 . Lub zog centripetal loj npaum li cas?

Paub:

Qhov hnyav (m) = 100 grams = 100/1000 kg = 1/10 kg = 0.1 kg

Qhov ceev ntawm lub kaum sab xis ( ω) = 4 radians/se cond

Lub vojvoog (r) = 50 cm = 50/100 m = 0.5 m

Xav tau: Centripetal force

Tshuaj:

Lub zog centripetal yog lub zog net uas ua rau muaj kev nrawm ntawm centripetal :

∑ F = ma _r

∑ F = mv ² /r = m ω ² r

∑ F = lub zog ntawm lub ntiajteb txawj nqus = lub zog ntawm lub ntiajteb txawj nqus , m = pawg , v = qhov ceev , ω = qhov ceev ntawm lub kaum sab xis , r = lub vojvoog

∑ F = m ω ² r = (0.1)(4) ² (0.5) = (0.1)(16)(0,5) = 0.8 Newtons

[irp]

2. Ib lub pob tig ib yam li qub hauv ib lub voj voog kab rov tav. Yog tias qhov ceev hloov mus rau plaub npaug ntawm tus nqi pib, qhov loj ntawm lub zog centripetal yog dab tsi…

Paub:

Qhov hnyav = m

Ceev = v

Qhov ceev pib = v _o

Lub vojvoog (r) = r

Xav tau: Qhov loj ntawm lub zog centripetal

Tshuaj:

3. Ib txoj kab nkhaus uas muaj radius R yog tsim los kom lub tsheb uas tsav tsheb nrog qhov ceev 12 ms ^–1 tuaj yeem tig mus rau qhov chaw nyab xeeb. Tus coefficient ntawm kev sib txhuam zoo li qub ntawm lub tsheb thiab txoj kev = 0.4. Radius R yog dab tsi. Kev nrawm vim lub ntiajteb txawj nqus ( g ) = 10 ms ^–2.

Paub:

Ceev (v) = 12 m/s

Cov coefficient ntawm kev sib txhuam zoo li qub ( μs ₎ = 0.4

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

Xav tau: Radius (R)

Tshuaj:

[irp]

[wpdm_package id='501′]

1. Qhov hnyav thiab qhov hnyav
2. ib txwm muaj zog
3. Newton txoj cai thib ob ntawm kev txav mus los
4. Lub zog sib txhuam
5. Kev txav mus los ntawm ib qho chaw kab rov tav yam tsis muaj kev sib txhuam
6. Kev txav ntawm ob lub cev nrog tib qhov kev nrawm ntawm qhov chaw ntxhib kab rov tav nrog lub zog sib txhuam
7. Kev txav mus los ntawm lub dav hlau inclined tsis muaj lub zog sib txhuam
8. Kev txav mus los ntawm lub dav hlau inclined nrog lub zog sib txhuam
9. Kev txav mus los hauv lub elevator
10. Kev txav ntawm lub cev yog txuas nrog los ntawm cov hlua thiab pulleys
11. Ob lub cev uas muaj tib lub zog ntawm kev nrawm
12. Kev sib hloov ntawm ib txoj kab tiaj tiaj - dynamics ntawm kev txav mus los ncig
13. Kev sib hloov ntawm cov kab nkhaus - dynamics ntawm kev txav mus los ncig
14. Kev txav mus los sib xws hauv lub voj voog kab rov tav
15. Lub zog centripetal hauv kev txav mus los sib npaug

nyeem ntxiv