physics

1. Qhov ntev ntawm daim iav convex yog 10 cm thiab qhov deb ntawm cov khoom yog 20 cm. Txheeb xyuas (a) qhov deb ntawm daim duab (b) qhov loj ntawm daim duab

Paub:

Qhov ntev ntawm lub focal (f) = -10 cm

Lub cim rho tawm qhia tias qhov chaw tseem ceeb ntawm daim iav convex yog virtual

Qhov nrug ntawm yam khoom ( d _o ) = 20 cm

Tshuaj:

Kev tsim cov duab los ntawm daim iav concave:

Qhov nrug ntawm daim duab (d _i ):

1/ hnub = 1/ _f – 1/ hnub = -1/10 – 1/20 = -2/20 – 1/20 = _-3/20

dia = -20/3 = -6.7 _cm

Lub cim rho tawm qhia tias daim duab yog virtual.

Kev loj hlob ntawm daim duab:

m = – di _/ do = -(-6.7)/20 = 6.7/20 ₌ 0.3

m = 0,3 npaug me dua li qhov khoom.

Lub cim ntxiv qhia tias daim duab nyob rau sab saud.

2. Muab ib yam khoom siab 10-cm tso rau ntawm daim iav convex uas muaj qhov ntev focal ntev li 20 cm. Txiav txim siab qhov siab ntawm daim duab yog tias qhov deb ntawm yam khoom yog (a) 10 cm (b) 30 cm (c) 40 cm (d) 50 cm

Paub:

Qhov ntev ntawm daim iav convex (f) = -20 cm

Lub cim rho tawm qhia tias qhov chaw tseem ceeb yog virtual

Lub vojvoog ntawm qhov nkhaus ( r ) = 2 f = 2(20) = 40 cm

Qhov siab ntawm yam khoom (h) = 10 cm

Tshuaj:

a) qhov ntev ntawm lub focal (f) = -20 cm thiab qhov deb ntawm yam khoom (d _o ) = 10 cm

Qhov nrug ntawm daim duab (d _i ) :

1/ hnub = 1/ _f – 1/ hnub = -1/20 – 1/10 = -1/20 – 2/20 = _-3/20

dia = -20/3 ₌ -6.7

Lub cim rho tawm qhia tias daim duab yog virtual lossis daim duab nyob tom qab daim iav.

Qhov loj ntawm daim duab ( m ):

m = – di _/ do = -(-6.7)/10 = 6.7/10 ₌ 0.67

Lub cim ntxiv qhia tias daim duab sawv ntsug.

Daim duab me dua li qhov khoom 0.67.

Qhov siab ntawm daim duab (h _i ):

m = h _i / h _o

h ₌ h _o m = (10 cm)(0.67) = 6.7 cm

b) qhov ntev ntawm lub focal (f) = -20 cm thiab qhov deb ntawm yam khoom ( d _o ) = 30 cm

Qhov nrug ntawm daim duab ( d _i ):

1/ di = 1/ _f – 1/ d0 = -1/20 – 1/30 = -3/60 – 2/60 = _-5/60

dia = -60/5 = _-12

Lub cim rho tawm qhia tias daim duab yog virtual lossis daim duab nyob tom qab daim iav.

Qhov loj ntawm daim duab ( m ):

m = – di _/ do ₌ -(-12)/30 = 12/30 = 0.4

Lub cim ntxiv qhia tias daim duab sawv ntsug.

Daim duab me dua 0,4 npaug ntawm yam khoom.

Qhov siab ntawm daim duab (h _i ):

m = h _i / h _o

h ₌ h _o m = (10 cm)(0.4) = 4 cm

c) Qhov ntev ntawm lub focal (f) = -20 cm thiab qhov deb ntawm yam khoom ( d _o ) = 40 cm

Qhov nrug ntawm daim duab ( d _i ):

1/ di = 1/ _f – 1/ d0 = -1/20 – 1/40 = -2/40 – 1/40 = _-3/40

dia = -40/3 ₌ -13.3

Lub cim rho tawm qhia tias daim duab yog virtual lossis daim duab nyob tom qab daim iav convex.

Qhov loj ntawm daim duab ( m ):

m = – di _/ do = -(-13.3)/40 = 13.3/40 ₌ 0.3

Lub cim ntxiv qhia tias daim duab sawv ntsug.

Daim duab me dua li qhov khoom 0.3.

Qhov siab ntawm daim duab ( h _{i )} :

m = h _i / h _o

h ₌ h _o m = (10 cm)(0.3) = 3 cm

d) Qhov ntev ntawm lub focal (f) = -20 cm thiab qhov deb ntawm yam khoom ( d _o ) = 50 cm

Qhov nrug ntawm daim duab ( d _i ):

1/ di = 1/ _f – 1/ d0 = -1/20 – 1/50 = -5/100 – 2/100 = _-7/100

dia = -100/7 ₌ -14.3

Lub cim rho tawm qhia tias daim duab yog virtual lossis daim duab nyob tom qab daim iav convex.

Qhov loj ntawm daim duab ( m ):

m = – di _/ do = -(-14.3)/50 = 14.3/50 ₌ 0.3

Lub cim ntxiv qhia tias daim duab sawv ntsug.

Daim duab me dua li qhov khoom 0.3.

Qhov siab ntawm daim duab (h _i ) :

m = h _i / h _o

h _i = h _o m = (10 cm)(0.3) = 3 cm

3. Ntawm yam khoom yog 20 cm nyob rau pem hauv ntej ntawm daim iav convex . Yog tias qhov siab ntawm daim duab yog 1/5 npaug ntawm qhov siab ntawm yam khoom, txiav txim siab ( a) qhov ntev ntawm daim duab b) qhov ntev focal c) cov yam ntxwv ntawm daim duab

Paub:

Qhov nrug ntawm yam khoom ( d _o ) = 20 cm

Qhov siab ntawm daim duab (h _i ) = 1/5 h = 0.2 h

Qhov siab ntawm yam khoom (h) = h

Tshuaj:

a) qhov deb ntawm daim duab ( d _i )

Cov mis ntawm kev loj hlob ntawm daim duab :

m = h _i / h _o = 0.2h / h = 0.2

Lub cim ntxiv qhia tias daim duab sawv ntsug.

Daim duab me dua li qhov khoom 0.2.

Qhov nrug ntawm daim duab ( d _i ):

– i = md _o​

dia ₌ – mdo ₌ -(0.2)(20 cm) = -4 cm

Lub cim rho tawm qhia tias daim duab yog virtual lossis daim duab nyob tom qab daim iav convex.

b) Qhov ntev ntawm lub focal ( f)

Qhov ntev ntawm lub focal (f):

_{1/ f} = 1/ d0 + 1/ d _i = 1/20 – 1/4 = 1/20 – 5/20 = -4/20

f = -20/4 = -5 cm

Lub cim rho tawm qhia tias qhov chaw tseem ceeb yog virtual.

c) Cov yam ntxwv ntawm daim duab:

- Ntsug

- Me dua

– virtual

4. Lub teeb ci ntsa iab rau daim iav convex uas sib luag rau lub axis yuav raug cuam tshuam….

A. mus rau qhov chaw tseem ceeb ntawm daim iav

B. raws li los ntawm qhov chaw tseem ceeb ntawm daim iav

C. dhau ntawm qhov chaw nruab nrab ntawm qhov nkhaus ntawm daim iav

D. perpendicular rau lub dav hlau iav

tshuaj

Qhov teeb meem tau kos rau hauv daim duab hauv qab no.

Cov lus teb yog B.

5. Ib tug neeg caij maus taus pom daim duab ntawm lub maus taus tom qab nws 1/6 npaug ntawm nws qhov loj qub thaum qhov deb ntawm tus neeg caij maus taus thiab maus taus yog 30 meters. Txheeb xyuas qhov radius ntawm curvature ntawm daim iav saib tom qab ...

A. 7.14 m

B. 8.57 m

C. 12.00 m

D. 24.00 m

Paub:

Kev loj ntawm daim duab (M) = 1/6 zaug

Qhov nrug ntawm yam khoom (d) = 30 meters

Xav tau: Lub vojvoog ntawm qhov nkhaus ntawm daim iav saib tom qab (R)

Tshuaj:

Xam qhov deb ntawm daim duab (d')

Vim tias qhov kev loj hlob ntawm daim duab (M) thiab qhov deb ntawm cov khoom (s) tau paub lawm, qhov kev ncua deb ntawm daim duab tuaj yeem paub siv cov mis ntawm kev loj hlob ntawm daim duab:

Lub cim tsis zoo txhais tau tias daim duab yog virtual. Daim duab nyob 5 meters tom qab daim iav convex.

Xam qhov ntev ntawm lub focal (f)

Vim tias qhov deb ntawm yam khoom (d) thiab qhov deb ntawm daim duab (d'), ces qhov ntev ntawm lub focal tuaj yeem suav los ntawm kev siv cov mis ntawm daim iav:

Lub vojvoog ntawm curvature (R)

Lub vojvoog ntawm curvature ntawm daim iav convex yog ob npaug ntawm qhov ntev ntawm daim iav convex.
R = 2 f = 2 (6 meters) = 12 meters
Lub vojvoog ntawm curvature ntawm daim iav convex yog 12 meters.
Cov lus teb yog C.

6. Daim iav convex raug xaiv los ua daim iav saib tom qab ntawm lub maus taus vim tias cov yam ntxwv ntawm daim duab tsim los ntawm daim iav yog ...

A. tiag tiag, ncaj nraim, txo qis

B. tiag tiag, ncaj nraim, nthuav dav

C. virtual, ncaj, txo qis

D. virtual, ncaj, nthuav dav

Tshuaj:

Raws li ob daim duab saum toj no nws tuaj yeem xaus lus tias cov khoom ntawm daim duab yog virtual, upright, minimized.

Cov lus teb yog C.

7. Ib yam khoom nyob deb li 12 cm ntawm daim iav convex uas muaj lub vojvoog ntawm 6 cm. Cov yam ntxwv ntawm daim duab yog...

A. tiag tiag, tig rov qab ntawm qhov deb ntawm 12 cm

B. tiag tiag, ncaj nraim ntawm qhov deb ntawm 4 cm

C. virtual, ncaj nraim ntawm qhov deb ntawm 2.4 cm

D. virtual, tig rov qab ntawm qhov deb ntawm 6 cm

Paub:

Qhov nrug ntawm yam khoom (d) = 12 cm

Lub vojvoog ntawm daim iav convex (r) = 6 cm.

Qhov ntev ntawm daim iav convex (f) = 6 cm / 2 = -3 cm

Qhov ntev ntawm daim iav convex yog kos npe tsis zoo vim nws yog virtual. Virtual vim nws tsis dhau los ntawm lub teeb.

Xav tau: Cov yam ntxwv ntawm daim duab

Tshuaj:

Qhov nrug ntawm daim duab (d'):

1/d' = 1/f – 1/d = -1/3 – 1/12 = -4/12 – 1/12 = -5/12

d' = -12/5 = -2.4 cm

Qhov nrug ntawm daim duab kos npe tsis zoo txhais tau tias daim duab yog virtual.

Kev loj ntawm daim duab (m):

m = -d' / d = -(-2.4) / 12 = 2.4 / 12 = 0.2 zaug

Qhov kev loj ntawm daim duab kos npe zoo txhais tau tias daim duab ncaj thiab qhov kev loj ntawm daim duab yog 0.2 txhais tau tias qhov loj ntawm daim duab me dua li qhov loj ntawm yam khoom (txo).

Cov lus teb yog C.

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1. Cov teeb meem thiab kev daws teeb meem ntawm daim iav concave
2. Cov teeb meem thiab kev daws teeb meem ntawm daim iav convex
3. Cov teeb meem thiab kev daws teeb meem ntawm cov lens sib txawv
4. Cov teeb meem thiab kev daws teeb meem ntawm Converging lens
5. Cov cuab yeej siv kho qhov muag teeb meem thiab kev daws teeb meem
6. Cov teeb meem thiab kev daws teeb meem ntawm cov iav sib cuag ntawm cov cuab yeej kho qhov muag
7. Cov tsom iav kho qhov muag
8. Cov teeb meem thiab kev daws teeb meem ntawm cov iav tsom iav kho qhov muag
9. Lub tshuab microscope kho qhov muag - teeb meem thiab kev daws teeb meem
10. Cov teeb meem thiab kev daws teeb meem ntawm cov cuab yeej siv kho qhov muag

nyeem ntxiv

1. Muab ib yam khoom tso rau ntawm daim iav uas nyob deb li ntawm 10 cm . Qhov ntev ntawm lub lens yog 5 cm. Txheeb xyuas seb (a) Qhov nrug ntawm daim duab yog dab tsi (b) qhov loj ntawm daim duab

Paub:

Qhov ntev ntawm lub teeb (f) = 5 cm

Qhov nrug ntawm yam khoom ( d _o ) = 10 cm

Kev daws teeb meem :

Kev tsim cov duab los ntawm daim iav concave:

Qhov nrug ntawm daim duab:

1/ hnub = 1/ _f – 1/ hnub = 1/5 – 1/10 = 2/10 – 1/10 = _1/10

dia ₌ 10/1 = 10 cm

Qhov nrug ntawm daim duab yog 10 cm.

Kev loj hlob:

_m = – die _/ die = -10/10 = -1

1 txhais tau tias daim duab zoo ib yam li cov khoom.

Lub cim rho tawm qhia tias daim duab tig rov qab. Yog tias lub cim zoo ces daim duab sawv ntsug.

2. Muab ib yam khoom siab 5-cm tso rau ntawm daim iav concave uas muaj lub vojvoog nkhaus li 20 cm. Txiav txim siab qhov siab ntawm daim duab yog tias qhov deb ntawm yam khoom yog 5 cm, 15 cm, 20 cm, 30 cm.

Paub:

Lub vojvoog ntawm qhov nkhaus ( r ) = 20 cm

Qhov ntev ntawm lub teeb (f) = R/2 = 20/2 = 10 cm

Qhov siab ntawm yam khoom ( _h₂o ) = 5 cm

Tshuaj:

a) qhov ntev ntawm lub focal (f) = 10 cm thiab qhov deb ntawm yam khoom ( d _o ) = 5 cm

Kev tsim cov duab los ntawm daim iav concave:

Qhov nrug ntawm daim duab ( d _i ):

1/ hnub = 1/ _f – 1/ hnub = 1/10 – 1/5 = 1/10 – 2/10 = _-1/10

dia = -10/1 = -10 _cm

Lub cim rho tawm qhia tias daim duab yog virtual lossis daim duab nyob tom qab daim iav.

Qhov loj ntawm daim duab ( m ):

m = – di _/ do ₌ -(-10)/5 = 10/5 = 2

Lub cim ntxiv qhia tias daim duab sawv ntsug.

Qhov siab ntawm daim duab ( h _i ):

m = h _i / h _o

h _i = h _o m = (5 cm)(2) = 10 cm

Daim duab siab yog 10 cm.

b) Qhov ntev ntawm lub teeb (f) = 10 cm thiab qhov deb ntawm yam khoom ( d _o ) = 15 cm

Kev tsim cov duab los ntawm daim iav concave:

Qhov nrug ntawm daim duab ( d _i ):

1/ hnub = 1/ _f – 1/ hnub = 1/10 – 1/15 = 3/30 – 2/30 = _1/30

dia ₌ 30/1 = 30 cm

Lub cim ntxiv qhia tias daim duab yog tiag tiag lossis daim duab nyob 30 cm ntawm pem hauv ntej ntawm daim iav, nyob rau tib sab ntawm yam khoom.

Qhov loj ntawm daim duab ( m ):

m = – die _/ die = -30/15 = _-2

Lub cim rho tawm qhia tias daim duab tig rov qab.

Daim duab loj dua 2 npaug ntawm qhov khoom.

Qhov siab ntawm daim duab (h _i ):

m = h _i / h _o

h _i = h _o m = (5 cm)(2) = 10 cm

Daim duab siab yog 10 cm.

c) Qhov ntev ntawm lub focal (f) = 10 cm thiab qhov deb ntawm yam khoom ( d _o ) = 20 cm

Kev tsim cov duab los ntawm daim iav concave:

Qhov nrug ntawm daim duab (d _i ):

1/ hnub = 1/ _f – 1/ hnub = 1/10 – 1/20 = 2/20 – 1/20 = _1/20

dia ₌ 20/1 = 20 cm

Lub cim zoo qhia tias daim duab yog tiag tiag lossis daim duab nyob 20 cm ntawm pem hauv ntej ntawm daim iav, nyob rau tib sab ntawm yam khoom.

Qhov loj ntawm daim duab ( m ):

m = – die _/ die = -20/20 = _-1

Lub cim tsis zoo txhais tau tias daim duab tig rov qab.

Qhov siab ntawm daim duab ( hi ):

m = h _i / h _o

h _i = h m = (5 cm)(1) = 5 cm

d) Qhov ntev ntawm lub focal (f) = 10 cm thiab qhov deb ntawm yam khoom ( d _o ) = 30 cm

Qhov nrug ntawm daim duab ( d _i ):

1/ hnub = 1/ _f – 1/ hnub = 1/10 – 1/30 = 3/30 – 1/30 = _2/30

dia ₌ 30/2 = 15 cm

Lub cim ntxiv qhia tias daim duab yog tiag tiag lossis daim duab nyob 15 cm ntawm pem hauv ntej ntawm daim iav, nyob rau tib sab ntawm yam khoom.

Qhov loj ntawm daim duab ( m) :

m = – die _/ die = -15/30 = _-0.5

Lub cim rho tawm qhia tias daim duab tig rov qab.

Daim duab me dua li qhov khoom 0.5.

Qhov siab ntawm daim duab (h _i ):

m = h _i / h _o

h _i = h _o m = (5 cm)(0.5) = 2.5 cm

3. Ib daim duab uas tsim los ntawm daim iav concave loj dua li yam khoom 4 npaug. Yog tias lub vojvoog ntawm qhov nkhaus yog 20 cm, txiav txim siab qhov deb ntawm yam khoom nyob rau pem hauv ntej ntawm daim iav!

Paub:

Qhov loj ntawm daim duab ( m ) = 4

Lub vojvoog ntawm qhov nkhaus ( r ) = 20 cm

Qhov ntev ntawm lub teeb (f) = r /2 = 20/2 = 10 cm

Xav tau : Qhov deb ntawm yam khoom ( d _o )

Tshuaj:

m = _– die _/ die​

4 = – d _{i /} d _o

– i = ₄ до_​

dia _{= –} 4 dia

_{1 /} f = 1/ d0 ₊ 1/ d1

1/10 = 1/ _DO + 1/4 _DO

4/40 = 4/4 ntawm _o + 1/4 ntawm _o

4/40 = 5/4 ntawm lub voj _voog

(4)(4s) = (5)(40)

16 hnub ₌ 200

d0 ₌ 12.5 cm

Qhov nrug ntawm cov khoom = 12.5 cm.

4. Muab ib yam khoom siab 1-cm tso rau ntawm daim iav concave 10 cm nrog qhov ntev f = 15 cm. Txheeb xyuas:

A. Qhov deb ntawm daim duab?

B. Qhov siab ntawm daim duab?

C. Cov yam ntxwv ntawm daim duab uas tsim los ntawm daim iav concave?

Paub:

Qhov siab ntawm yam khoom (h) = 1 cm

Qhov nrug ntawm yam khoom (d _o ) = 10 cm

Qhov ntev ntawm daim iav concave (f) = 15 cm

Tshuaj:

A. Qhov nrug ntawm daim duab (d _i )

1/f = 1/hnub ₊ 1/ _hnub

1/hnub ₌ 1/f – 1/hnub ₌ 1/15 – 1/10 = 2/30 – 3/30 = -1/30

dia = -30/1 ₌ -30 cm

Lub cim tsis zoo qhia tias daim duab yog virtual lossis daim duab nyob tom qab daim iav.

B. Qhov siab ntawm daim duab (h _i )

Qhov loj ntawm daim duab (M):

M = _-di / _do = _hi / _ho

M = -(-30)/10 = 30/10 = 3 zaug

Qhov siab ntawm daim duab (h _i ):

M = h _i / h _o

3 = h _i / 1 cm

h ₌ 3 (1 cm)

h ₌ 3 cm

daim duab siab yog 3 cm. Lub cim ntxiv qhia tias daim duab nyob rau sab saud.

C. Cov yam ntxwv ntawm daim duab:

Virtual, upward, loj dua li khoom

5. Qhov loj ntawm daim duab, raws li daim duab hauv qab no.

Paub:

Qhov nrug ntawm yam khoom (d _o ) = 60 cm

Qhov ntev ntawm lub teeb (f) = 20 cm

Xav tau: Qhov loj ntawm daim duab (M)

Tshuaj:

Qhov nrug ntawm daim duab:

1/f = 1/hnub ₊ 1/ _hnub

1/hnub ₌ 1/f – 1/hnub ₌ 1/20 cm – 1/60 cm = 3/60 cm – 1/60 cm = 2/60 cm

dia = 60/2 cm ₌ 30 cm

Qhov loj ntawm daim duab (M):

M = di _/ d ₌ 30 cm / 60 cm = 1/2 zaug

6. Yog tias muab yam khoom tso rau 6 cm ntawm daim iav concave, qhov deb ntawm daim duab yog 12 cm raws li qhia hauv daim duab hauv qab no. Yog tias yam khoom raug tsiv ntawm qhov chaw qub 1 cm ntawm daim iav, qhov deb ntawm daim duab yog dab tsi.

Paub:

Qhov nrug ntawm yam khoom (d _o ) = 6 cm

Qhov nrug ntawm daim duab (d _i ) = 12 cm

Xav tau: yog tias qhov deb ntawm yam khoom (d _o ) = 7 cm ces qhov deb ntawm daim duab yog ...

Tshuaj:

1/f = 1/do + 1/di = 1/6 + 1/12 = 2/12 + 1/12 = 3/12

f = 12/3 = 4 cm

Qhov ntev ntawm lub teeb yog qhov zoo, txhais tau tias qhov chaw tsom kwm yog qhov tseeb lossis cov duab ci dhau los ntawm qhov ntawd.

Qhov nrug ntawm daim duab:

1/hnub ₌ 1/f – 1/hnub ₌ 1/4 – 1/7 = 7/28 – 4/28 = 3/28

dia ₌ 28/3 = 9.3 cm

7. Tus kws kho hniav siv daim iav uas muaj 8 cm radius los saib thiab kuaj xyuas cov hniav ntawm tus neeg mob. Yuav kom tus kws kho mob pom tau lub qhov kom meej, qhov deb ntawm tus neeg mob cov hniav thiab daim iav yog dab tsi?

A. tsawg dua 4 cm nyob rau pem hauv ntej ntawm daim iav concave

B. tsawg dua 4 cm nyob rau pem hauv ntej ntawm daim iav convex

C. ntau tshaj 4 cm nyob rau pem hauv ntej ntawm daim iav concave

D. ntau tshaj 4 cm nyob rau pem hauv ntej ntawm daim iav convex

Paub:

Lub vojvoog ntawm daim iav (r) = 8 cm

Qhov ntev ntawm daim iav (f) = r / 2 = 8 / 2 = 4 cm

Xav tau: Qhov deb ntawm tus neeg mob cov hniav thiab daim iav

Tshuaj:

Daim iav siv yog daim iav concave los yog daim iav convex? Yuav kom tus kws kho mob pom qhov hniav meej, daim iav siv yuav tsum ua kom daim duab ntawm tus hniav loj dua thiab daim duab yuav tsum ncaj. Daim iav convex ib txwm tsim cov duab tig rov qab thiab qhov loj ntawm daim duab me dua qhov loj ntawm yam khoom. Ntawm qhov tod tes, daim iav concave tuaj yeem tsim cov duab ncaj yog tias qhov deb ntawm yam khoom (d) me dua qhov ntev focal (f). Yog tias qhov deb ntawm yam khoom loj dua qhov ntev focal (f) ces daim iav concave tsim cov duab tig rov qab.

Qhov ntev focal (f) ntawm daim iav concave yog 4 cm, yog li ntawd tus neeg mob cov hniav yuav tsum tsawg dua 4 cm nyob rau pem hauv ntej ntawm daim iav concave.

Cov lus teb yog lawm yog A.

8. Ib daim iav concave muaj lub vojvoog ntawm qhov nkhaus ntawm 24 cm. Yog tias qhov khoom raug tso 20 cm rau ntawm daim iav ces txiav txim siab cov yam ntxwv ntawm daim duab.

A. Tiag tiag, ncaj thiab loj dua

B. Tiag tiag, tig rov qab thiab nthuav dav

C. Virtual, upright thiab loj dua

D. Virtual, tig rov qab thiab me dua

Paub:

Lub vojvoog ntawm qhov nkhaus (r) = 24 cm

Qhov ntev ntawm lub teeb (f) = R/2 = 24/2 = +12 cm

Qhov ntev ntawm daim iav concave yog qhov zoo lossis qhov tseeb vim tias lub teeb hla dhau qhov chaw ntawm daim iav.

Qhov nrug ntawm yam khoom (d) = 20 cm

Xav tau: Cov yam ntxwv ntawm daim duab

Tshuaj:

Daim duab yog duab tiag los yog duab tiag? Xam qhov deb ntawm daim duab (s'):

1/hnub + 1/hnub' = 1/f

1/hnub' = 1/f – 1/hnub

1/d' = 1/12 – 1/20

1/d' = 5/60 – 3/60

1/d' = 2/60

d' = 60/2

d' = 30 cm

Qhov nrug ntawm daim duab kos npe zoo txhais tau tias daim duab yog tiag tiag vim nws raug lub teeb hla dhau.

Duab loj dua? Sawv ntsug los yog tig rov qab? Ua ntej xam qhov loj ntawm daim duab (M):

M = -d' / d = -30/20 = -1.5

M > 1 txhais tau tias daim duab loj dua, M muaj lub cim tsis zoo txhais tau tias daim duab tig rov qab. Yog li cov yam ntxwv ntawm daim duab yog tiag tiag, tig rov qab, nthuav dav.

Cov lus teb yog B.

9. Ib daim iav kheej kheej tsim ib daim duab uas loj dua 5 npaug ntawm qhov khoom ntawm lub vijtsam, 5 meters ntawm qhov khoom. Daim iav yog…..

A. concave nrog lub focal ntev ntawm 25/24 m

B. convex nrog lub focal ntev ntawm 25/24 m

C. concave nrog lub focal ntev ntawm 24/25 m

D. convex nrog lub focal ntev ntawm 24/25 m

Paub:

Kev loj ntawm daim duab (M) = 5 zaug

Qhov nrug ntawm yam khoom thiab daim duab = 5 meters

Tshuaj:

Qhov loj ntawm daim duab uas tsim los ntawm daim iav convex yeej ib txwm me dua li qhov loj ntawm cov khoom, yog li ntawd, daim iav yog daim iav concave.

Qhov nrug ntawm yam khoom (d) = x

Qhov nrug ntawm daim duab (d') = x + 5

Kev loj ntawm daim duab (M) = 5 zaug

Cov qauv ntawm kev loj hlob ntawm daim duab:

Tus qauv ntawm qhov ntev focal (f):

Cov lus teb yog lawm yog A.

[wpdm_package id='858′]

1. Cov teeb meem thiab kev daws teeb meem ntawm daim iav concave
2. Cov teeb meem thiab kev daws teeb meem ntawm daim iav convex
3. Cov teeb meem thiab kev daws teeb meem ntawm cov lens sib txawv
4. Cov teeb meem thiab kev daws teeb meem ntawm Converging lens
5. Cov cuab yeej siv kho qhov muag teeb meem thiab kev daws teeb meem
6. Cov teeb meem thiab kev daws teeb meem ntawm cov iav sib cuag ntawm cov cuab yeej kho qhov muag
7. Cov tsom iav kho qhov muag
8. Cov teeb meem thiab kev daws teeb meem ntawm cov iav tsom iav kho qhov muag
9. Lub tshuab microscope kho qhov muag - teeb meem thiab kev daws teeb meem
10. Cov teeb meem thiab kev daws teeb meem ntawm cov cuab yeej siv kho qhov muag

nyeem ntxiv

1. 1-kg dej ntawm 100 ^o C sib xyaw nrog 1-kg dej ntawm 10 ^o C hauv ib lub kaw lus cais tawm. Lub cua sov tshwj xeeb ntawm dej yog 4200 J/kg ^o C. Txheeb xyuas qhov kub kawg ntawm qhov sib tov!

Paub:

Qhov hnyav ntawm dej kub (m1 ₎ = 1 kg

Kub ntawm dej kub (T ₁ ) = 100 ^o C

Qhov hnyav ntawm dej txias (m2 ₎ = 1 kg

Kub ntawm dej txias (T2 ₎ = 10 ^o C

Xav tau: Qhov kub kawg (T)

Tshuaj:

Kub poob = Kub tau (lub kaw lus cais)

mc Δ T = mc Δ T​

m Δ T = m Δ T

m ₁ (T ₁ – T) = m ₂ (T – T ₂ )

(1)(100 – T) = (1)(T – 10)

100 – T = T – 10

100 + 10 = T + T

110 = 2T

T = 110 / 2

TXL = 55

Qhov kub kawg yog 55 ^o C.

2. Ib lub pob zeb lead 3 kg ntawm 80^o muab tso rau hauv 10 kg dej. Lub cua sov tshwj xeeb ntawm cov hlau lead yog 1400 J.kg^-1C^-1 thiab qhov kub tshwj xeeb ntawm dej yog 4200 J.kg^-1C^-1Qhov kub kawg hauv qhov sib npaug ntawm thermal yog 20^oC. Txheeb xyuas qhov kub pib ntawm dej!

Paub:

Qhov hnyav (m1 ₎ = 3 kg

Lub cua sov tshwj xeeb ntawm cov hlau lead (c1 ₎ = 1400 J.kg ^-1 C ^-1

Qhov kub ntawm cov hlau txhuas (T1 ₎ = 80 ^o C

Qhov hnyav ntawm dej (m2 ₎ = 10 kg

Lub cua sov tshwj xeeb ntawm dej (c2 ₎ = 4200 J.kg ^-1 C ^-1

Qhov kub ntawm thermal equilibrium (T) = 20 ^o C

Xav tau: Qhov kub pib ntawm dej (T ₂ )

Tshuaj:

Kub poob = Kub tau

Q txhuas = Q dej

m ₁ c ₁ ΔT = m ₂ c ₂ ΔT

(3)(1400)(80-20) = (10)(4200)(20-T)

(4200)(60) = (42,000)(20-T)

252,000 = 840,000 – 42,000 T

42,000 T = 840,000 – 252,000

42,000 T = 588,000

T = 588,000 / 42,000

TXL = 14

Qhov kub pib ntawm dej yog 14 ^o C.

3. Ib lub thaiv tooj liab ntawm 100^oC muab tso rau hauv 128 grams dej ntawm 30 ^oC. Qhov kub tshwj xeeb ntawm dej yog 1 cal.g^{-1 Nws}C^-1 thiab qhov kub tshwj xeeb ntawm tooj liab yog 0.1 cal.g^{-1 Nws}C^-1. Yog tias qhov kub ntawm qhov sib npaug ntawm thermal yog 36 ^oC, txiav txim siab qhov hnyav ntawm cov tooj liab!

Paub:

Qhov kub ntawm tooj liab (T1 ₎ = 100 ^o C

Lub cua sov tshwj xeeb ntawm tooj liab ⁽ c1 ₎ = 0.1 cal.g -1o ^C -1

Qhov hnyav ntawm dej (m2 ₎ = 128 grams

Kub ntawm dej (T2 ₎ = 30 ^o C

Qhov kub tshwj xeeb ntawm dej (c2 ₎ = 1 c al.g ^-1o C ^-1

Qhov kub ntawm thermal equilibrium (T) = 36 ^o C

Xav tau: Qhov hnyav ntawm tooj liab (m ₁ )

Tshuaj:

Kub poob = Kub tau

Q tooj liab = Q dej

m ₁ c ₁ ΔT = m ₂ c ₂ ΔT

(m ₁ )(0.1)(100-36) = (128)(1)(36-30)

(m ₁ )(0.1)(64) = (128)(1)(6)

(m ₁ )(6.4) = 768

m ₁ = 768 / 6.4

m ₁ = 120

Qhov hnyav ntawm cov txiv hmab txiv ntoo yog 120 grams.

4. Ib lub pob dej khov M-kg ntawm 0^oC muab tso rau hauv 340 grams dej ntawm 20^oC nyob rau hauv ib lub thawv. Yog tias lub cua sov ntawm kev sib xyaw rau dej = 80 calories g^-1, qhov kub tshwj xeeb ntawm dej yog 1 calorie g^{-1 o}C^-1. Tag nrho cov dej khov yaj thiab qhov kub ntawm kev sib npaug ntawm thermal is 5^oC, txiav txim seb qhov loj ntawm dej khov loj npaum li cas!

Paub:

Qhov hnyav ntawm dej (m) = 340 grams

Qhov kub ntawm dej khov (T _{dej khov} ) = 0 ^o C

Qhov kub ntawm dej (T _dej ) = 20 ^o C

Qhov kub ntawm thermal equilibrium (T) = 5 ^o C

Lub cua sov ntawm kev sib xyaw rau dej ( L ) = 80 c al g ^-1

Qhov kub tshwj xeeb ntawm dej (c _dej ) = 1 cal g ^{-1 o} C ^-1

Xav tau: Qhov hnyav ntawm dej khov (M)

Tshuaj:

Kub poob = Kub tau

Q dej = Q dej khov

m c ( ΔT ) = m _es L _es + m c ( Δ T )

(340)(1)(20-5) = M (80) + M (1)(5-0)

(340)(15) = 80M + 5M

5100 = 85M

M = 5100/85

M = 60 grams

[wpdm_package id='714′]

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

4 Qhov Kub Latent Qhov Kub ntawm Kev Sib Xyaws Qhov Kub ntawm Kev Ua Pa - Teeb Meem thiab Kev Dais Teeb Meem

1. Xam qhov kub uas ntxiv rau 1 gram kub kom hloov theem ntawm cov khoom khov mus rau cov kua. Qhov kub ntawm kev sib xyaw rau kub yog 64.5 x 10 ³ J/kg.

Paub:

Qhov hnyav (m) = 1 gram = 1 x 10 ^-3 kg

Lub cua sov ntawm kev sib xyaw (L₂F ₎ = 64.5 x 10₂ ^J /kg

Xav tau: Kub (Q)

Tshuaj:

Q = m L _F

Q = (1 x 10 ^-3 kg)(64.5 x 10 ³ J/kg)

Q = 64.5 Joules

2. Xam qhov kub uas 1 gram ntawm mercury tso tawm los hloov theem ntawm kua mus rau khoom khov. Qhov kub ntawm kev sib xyaw rau mercury yog 11.8 x 10 ³ J/kg.

Paub:

Qhov hnyav (m) = 1 gram = 1 x 10 ^-3 kg

Lub cua sov ntawm kev sib xyaw (L₂F ₎ = 11.8 x 10₂ ^J /kg

Xav tau: Kub (Q)

Tshuaj:

Q = m L _F

Q = (1 x 10 ^-3 kg)(11.8 x 10 ³ J/kg)

Q = 11.8 Joules

3. Txheeb xyuas seb 1 kg dej nqus tau cua sov npaum li cas los hloov theem ntawm kua mus rau pa (pas dej). Cua sov ntawm kev ua pa rau dej = 2256 x 10 ³ J/kg

Paub:

Qhov hnyav (m) = 1 kg

Lub zog cua sov ntawm kev ua pa (LV ₎ = 2256 x 10 ³ J/kg

Xav tau: Kub (Q)

Tshuaj:

Q = m L _V

Q = (1 kg)( 2256 x 10 ³ J/kg)

Q = 2256 x 10 ³ Joule

4. Txheeb xyuas seb nitrogen tso tawm cua sov ntau npaum li cas los hloov theem ntawm pa mus rau kua. Cua sov ntawm kev ua pa rau nitrogen = 200 x 10 ³ J/kg

Paub:

Qhov hnyav (m) = 1 gram = 1 x 10 ^-3 kg

Lub zog cua sov ntawm kev ua pa (LV ₎ = 200 x 10 ³ J/kg

Paub: Kub (Q)

Tshuaj:

Q = m L _V

Q = (1 x 10 ^-3 kg) ( 200 x 10 ³ J/kg)

Q = 200 Joules

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. Ib lub cev uas hnyav 2 kg nqus tau 100 calories thaum nws qhov kub nce ntawm 20 ^o C mus rau 70 o ^C. Lub cev qhov kub tshwj xeeb yog dab tsi ?

Paub:

Qhov hnyav (m) = 2 kg = 2000 gr

Kub (Q) = 100 c al

Qhov kev hloov pauv ntawm qhov kub thiab txias ( ΔT ) = 70 ^o C – 20 ^o C = 50 ^o C

Xav tau: Qhov kub tshwj xeeb (c)

Tshuaj:

c = Q / m Δ T

c = 100 calorie / (2000 gr)(50 ^o C)

c = 100 calorie / 100,000 gr ^o C

c = 10 ² calorie / 10 ⁵ gr ^o C

c = (10 ² calorie)( 10 ^-5 gr ^{-1 o} C ^-1 )

c = 10 ^-3 cal gr ^{-1 o} C ^-1

c = 10 ^-3 cal/ gr ^o C

Lub cev kub tshwj xeeb yog ^10-3 cal /g ^° C

2. Lub cua sov tshwj xeeb ntawm dej yog 4180 J/kg C ^o . Muaj peev xwm cua sov npaum li cas ntawm 2 kg dej…

Paub:

Qhov kub tshwj xeeb (c) = 4180 J/kg C ^o

Qhov hnyav (m) = 2 kg

Xav tau: Muaj peev xwm kub (C)

Tshuaj:

C = mc

C = (2 kg) (4180 J/kg ^C₂O₃ )

C = (2)(4180 J/ ^C₂O )

C = 8360 J/ ^C₂O

3. Lub cua sov tshwj xeeb ntawm txhuas yog 900 J/kg Co ^o . Muaj pes tsawg lub peev xwm cua sov ntawm 2 gram txhuas…..

Paub:

Lub cua sov tshwj xeeb ntawm txhuas (c) = 900 J/kg Co₂O ⁼ 9 x 10₃2 ^J /kg ^Co₂O

Qhov hnyav (m) = 2 grams = 2/1000 kg = 2/10 ³ kg = 2 x 10 ^-3 kg

Xav tau: Muaj peev xwm kub (C)

Tshuaj:

C = mc

C = (2 x 10 ^-3 kg)( 9 x 10 ² J/kg C ^o )

C = 18 x 10 ^-3 x 10 ² J/C ^o

C = 18 x 10 ^-1 J/ ^C₂O

C = 1.8 J/ ^C₂O

[wpdm_package id='710′]

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. 2 k calorie (kilo c calorie e ) = ….. c calorie e?

tshuaj

1 kcal = 1000 kcal

2 kcal = 2 (1000 kcal e ) = 2000 kcal e

2. 4 C calorie e = …..c calorie e?

tshuaj

1 Calori e ( a Capital C ) = 1 k cal = 1000 calori e

4 C calorie e = 4 (1000 c calorie e ) = 4000 c calorie e

3. 10 c calorie e =…..Jul?

tshuaj

1 calorie e = 4.186 Joules

10 c calorie e = 10 (4.186 Joules) = 41.86 Joules

4. 5 kcal = ….. Joule ?

tshuaj

1 kcal = 1000 c alorie = 4186 Joules

5 kcal = 5 (4186 Joules) = 20930 Joules

5. 2000 Joules = ….. kcal?

tshuaj

4186 Joules = 1 kcal

8372 Joules = 8372 / 4186 = 2 kcal

2000 Joules = 2000 / 4186 = 0.4777 kcal

[wpdm_package id='706′]

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

9 Qhov Kub Qhov Loj Qhov kub tshwj xeeb Qhov kev hloov pauv ntawm qhov kub thiab txias - Teeb Meem thiab Kev Dais Teeb Meem

1. Ib tug 2 kg lead yog cua sov los ntawm 50^oC rau 100^oC. Tus lub tshav kub tshwj xeeb ntawm cov hlau lead yog 130 J.kg^{-1 o}C^-1. Npaum licas Thaum tshav kub kub puas yog cov hlau lead nqus tau?

Paub:

Qhov hnyav (m) = 2 kg

Qhov kub tshwj xeeb (c) = 1 3 0 J.kg ^-1 C ^-1

Qhov kev hloov pauv ntawm qhov kub thiab txias ( Δ T) = 100 ^o C – 50 ^o C = 50 ^o C

Xav tau: Kub (Q)

Tshuaj:

Q = mc Δ T

Q = cua sov , m = pawg, c = cua sov tshwj xeeb , Δ T = kev hloov pauv ntawm qhov kub thiab txias

Cov cua sov uas cov hlau lead nqus tau:

Q = (2 kg)(1 3 0 J.kg ^-1 C ^-1 )(50 ^o C)

Q = (100)(1 3 0)

Q = 1 3,000 Joules

Q = 1.3 x ¹⁰⁴ Joules

2. Lub cua sov tshwj xeeb ntawm tooj liab yog 390 J/k g ^o C, qhov kev hloov pauv ntawm qhov kub thiab txias yog 40 ^o C. Yog tias tooj liab nqus tau 40 Joules ntawm cua sov, qhov hnyav ntawm tooj liab yog dab tsi!

Paub:

Lub cua sov tshwj xeeb ntawm tooj liab (c) = 390 J/ kg ^o C

Qhov kev hloov pauv ntawm qhov kub thiab txias ( ΔT ) = 40 ^o C

Kub ( Q) = 40 J

Xav tau: Qhov hnyav (m) ntawm tooj liab

Tshuaj:

Q = mc Δ T

40 J = (m)( 390 J/k g ^o C)(40 ^o C)

40 = (m)( 390 /kg )(40)

40 = (m)( 390 /kg )(4)

40 = (m)( 1560 /kg )

m = 40 / 1560

m = 0.026 kg

m = 26 grams

3. Qhov kub pib ntawm 20 grams dej yog 30 ^o C. Qhov kub tshwj xeeb ntawm dej yog 1 cal g ^{-1 o} C ^-1 . Yog tias dej nqus tau 300 calories ntawm qhov kub, txiav txim siab qhov kub kawg!

Paub:

Qhov hnyav (m) = 20 gr

Qhov kub pib (T ₁ ) = 30 ^o C

Qhov kub tshwj xeeb ntawm dej (c) = 1 cal gr ^{-1 o} C ^-1

Kub (Q) = 300 calorie

Xav tau: Qhov kub kawg ntawm dej

Tshuaj:

Q = mc ΔT

300 calories = (20 gr)( 1 calories gr ^{-1 o} C ^-1 )( T ₂ -30 )

300 = (20)(1)( T ₂ -30)

300 = 20 ( T ₂ -30 )

300 = 20 T ₂ – 600

300 + 600 = 20T ₂

900 = 20T ₂

T ₂ = 900 / 20

T ₂ = 45

Qhov kev hloov pauv ntawm qhov kub thiab txias yog 45 ^o C – 30 ^o C = 15 ^o C.

4. Tqhov kev hloov pauv ntawm qhov kub thiab txias ntawm dej hiav txwv is 1^oC thaum dej nqus tau 3900 Joules ntawm cua sov. Lub cua sov tshwj xeeb ntawm dej hiav txwv yog 3.9 × 10³ J/kg°C, qhov loj ntawm dej hiav txwv yog dab tsi.

Paub:

Qhov kev hloov pauv ntawm qhov kub thiab txias ( ΔT ) = 1 ^o C

Kub (Q) = 3900 Joule

Qhov kub tshwj xeeb ntawm dej hiav txwv (c) = 3.9 x 10 ³ J/ k g°C = 3900 J/Kg°C

Qhov Loj: (m)

Tshuaj:

Q = mc Δ T

Q = cua sov , m = pawg, c = cua sov tshwj xeeb , Δ T = qhov hloov pauv ntawm qhov kub thiab txias

m = Q / c Δ T = 3900 / (3900)(1) = 3900 / 3900 = 1 kg

5. Ib lub tooj liab hnyav 2-kg nqus tau 39,000 J ntawm cua sov ntawm 30°C. Yog tias qhov cua sov tshwj xeeb ntawm tooj liab yog 390 J/kg °C, qhov kub kawg ntawm tooj liab yog dab tsi …

Paub:

Qhov hnyav (m) = 2 kg

Kub pib (T1 ₎ = 30 ^o C

Kub (Q) = 39,000 Joule

Cov cua sov tshwj xeeb (c) ntawm tooj liab = 390 J/kg ^o C

Xav tau : Qhov kub kawg (T ₂ )

Tshuaj:

Q = mc ΔT

Q = cua sov , m = pawg, c = cua sov tshwj xeeb , ΔT = qhov hloov pauv ntawm qhov kub thiab txias

Q = mc ΔT = mc ( _T2 – _T1 )

39,000 = (2)( 390)(T ₂ – 30)

100 = (2)(1)(T ₂ – 30)

100 = (2)(T ₂ – 30)

50 = T ₂ – 30

T ₂ = 50 + 30

T2 = 80 ^oC_​

6. Ib dej hnyav 5 kg raug cua sov ntawm 15°C mus txog 40°C. Dej nqus cua sov npaum li cas. Qhov kub tshwj xeeb ntawm dej yog 4.2 × 10 ³ J/Kg° C.

Paub:

Qhov hnyav (m) = 5 kg

Kub pib (T ₁ ) = 15°C

Qhov kub kawg (T ₂ ) = 40°C

Qhov kub tshwj xeeb ntawm dej (c) = 4.2 × 10 ³ J/kg° C

Xav tau: Kub (Q)

Tshuaj:

Q = mc ΔT

Q = (5 kg)( 4.2 × 10 ³ J/kg°C)(40°C – 15°C)

Q = (5)( 4.2 × 10 ³ J)(25)

Q = 525 x 10 ³ J

Q = 525,000 Joules

7. Ib dej hnyav 2 kg raug cua sov ntawm 24°C mus txog 90°C. Dej nqus cua sov npaum li cas. Qhov kub tshwj xeeb ntawm dej yog 4.2 × 10 ³ J/Kg° C.

Paub:

Qhov hnyav (m) = 2 kg

Kub pib (T ₁ ) = 24°C

Qhov kub kawg (T ₂ ) = 90°C

Cov cua sov tshwj xeeb ntawm dej (c) = 4,200 Joules/kg°C

Xav tau :: Kub (Q)

Tshuaj:

Q = mc ΔT

Q = (2 kg)( 4,200 Joules/kg°C)(90°C – 24°C)

Q = (2 kg)( 4,200 Joules/kg°C)(66°C)

Q = (132)( 4,200 Joules)

Q = 554,400 Joules

8. Ib tug dej 5-gram raug cua sov ntawm 10°C mus txog 40°C. Dej nqus tau cua sov npaum li cas. Qhov kub tshwj xeeb ntawm dej yog 1 × 10 ³ cal / g r ° C.

Paub:

Qhov hnyav (m) = 5 grams

Kub pib (T1 ₎ = 10 ^o C

Qhov kub kawg (T2 ₎ = 40 ^o C

Qhov kub tshwj xeeb ntawm dej (c) = 1 c al / gr°C

Xav tau : Kub

Tshuaj:

Q = mc ΔT

Q = (5 grams) ( 1 cal/ gr°C) (40 ^o C – 10 ^o C)

Q = (5)( 1 c al)(30)

Q = 150 calories

9. Ib dej hnyav 0.2 -kg nqus tau 42,000 Joules ntawm qhov kub 25 ^o C. Qhov kub tshwj xeeb ntawm dej yog 4200 J/kg ^o C, qhov kub kawg ntawm dej yog dab tsi.

Paub:

Qhov hnyav ntawm dej (m) = 0.2 kg

Kub (Q) = 42,000 Joule

Cov cua sov tshwj xeeb ntawm dej (c) = 4200 J/kg ^o C

Kub pib (T1 ₎ = 25 ^o C

Xav tau: Qhov kub kawg (T ₂ )

Tshuaj:

Q = mc ΔT = mc ( _T2 – _T1 )

Q = Thaum tshav kub kub, m = pawg, c = lub tshav kub tshwj xeeb, ΔT = qhov kev hloov pauv ntawm qhov kub thiab txias, T₁ = qhov kub pib, T₂ = qhov kub kawg

Q = mc ( _T2 – _T1 )

42,000 = (0.2)(4200)(T ₂ – 25)

42,000 = 840 (T ₂ – 25)

42,000 = 840 T ₂ – 21,000

42,000 + 21,000 = 840 T ₂

63,000 = 840 T ₂

T ₂ = 63,000 / 840

T2 = 75 ^oC_​

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

Tsuas yog cov khoom khov kho xwb thiaj li muaj kev nthuav dav linear; txhua yam khoom, ob qho tib si khov kho, kua, thiab roj, kuj muaj kev nthuav dav volume. Cov qauv ntawm kev nthuav dav volume zoo ib yam li cov qauv ntawm kev nthuav dav linear.

Kev Piav Qhia: V _o = Qhov Ntim Pib, V = Qhov Ntim Kawg, ΔV = V – V _o = Qhov kev hloov pauv ntawm qhov ntim, T _o = Qhov kub pib, T = Qhov kub kawg, ΔT = T – T _o = Qhov kev hloov pauv ntawm qhov kub, β = tus coefficient ntawm kev nthuav dav ntawm qhov ntim. Cov chav ntawm β = (C ^o ) ^-1

Tus qauv kev nthuav dav ntim saum toj no tsuas yog siv tau thaum qhov kev hloov pauv ntawm qhov ntim ntawm cov khoom (ob qho tib si khoom khov, kua, thiab roj) me dua li qhov ntim thawj ntawm cov khoom. Yog tias qhov kev hloov pauv ntawm qhov ntim ntawm ib yam khoom loj dua li qhov ntim pib ntawm cov khoom, tus qauv ntawm qhov kev nthuav dav ntim tsis muab cov txiaj ntsig zoo. Feem ntau, qhov kev hloov pauv ntawm qhov ntim uas cov khoom khov ntsib tsis loj dhau. Ntawm qhov tod tes, tus coefficient ntawm qhov ntim nthuav dav ntawm cov kua thiab roj yog loj. Tus coefficient ntawm qhov ntim nthuav dav rau cov khoom roj kuj yooj yim hloov pauv yog tias qhov kub hloov pauv. Yog li ntawd, tus qauv saum toj no tsuas yog siv rau qhov kev nthuav dav ntawm cov khoom khov.

1. Thaum 30 ^o C qhov ntim ntawm lub pob zeb txhuas yog 30 cm ^3. Tus coefficient ntawm kev nthuav dav linear yog 24 x 10 ^{-6 o} C ^-1 . Yog tias qhov ntim kawg yog 30.5 cm ³ , qhov kub kawg ntawm lub pob zeb txhuas yog dab tsi?

Paub:

Tus coefficient ntawm linear expansion ( α ) = 24 x 10 ^{-6 o} C ^-1

Tus coefficient ntawm kev nthuav dav ntim ( β ) = 3 α = 3 x 24 x 10 ^{-6 o} C ^-1 = 72 x 10 ^{-6 o} C ^-1

Qhov kub pib (T ₁ ) = 30 ^o C

Qhov ntim pib (V ₁ ) = 30 cm ³

Qhov ntim kawg (V ₂ ) = 30.5 cm ³

Qhov kev hloov pauv ntawm qhov ntim ( Δ V) = 30.5 cm ³ – 30 cm ³ = 0.5 cm ³

Xav tau: Qhov kub kawg (T ₂ )

Tshuaj:

Δ V = β (V1 ₎ ( ΔT )

Δ V = β (V1 ₎ ( _T2 – _T1 )

0.5 cm³ = (72 x 10^{-6 o}C^-1)(30 cm³)(T₂ - 30^oC)

0.5 = (2160 x 10 ^-6 ) (T ₂ – 30 )

0.5 = (2.160 x 10 ^-3 ) (T 2 – 30 )

0.5 = (2.160 x 10 ^-3 ) (T ₂ – 30 )

0.5 / (2.160 x 10 ^-3 ) = T ₂ – 30

0.23 x 10 ³ = T ₂ – 30

0.23 x 1000 = T ₂ – 30

230 = T ₂ – 30

230 + 30 = T ₂

T2 = 260 ^oC_​

2. Tus coefficient ntawm linear expansion ntawm lub pob hlau yog 9 x 10 ^{-6 o} C ^-1 . Lub cheeb sab hauv ntawm lub pob hlau ntawm 20 ^o C yog 2.2 cm. Yog tias lub cheeb kawg yog 2.8 cm, qhov kub kawg yog dab tsi!

Paub:

Tus coefficient ntawm linear expansion ( α ) = 9 x 10 ^{-6 o} C ^-1

Tus coefficient ntawm kev nthuav dav ntim ( β) = 3 α = 3 x 9 x 10 ^{-6 o} C ^-1 = 27 x 10 ^{-6 o} C ^-1

Qhov kub pib (T ₁ ) = 20 ^o C

Lub taub hau pib (D ₁ ) = 2.2 cm

Qhov kawg txoj kab uas hla (D ₂ ) = 2.8 cm

Lub vojvoog pib (r ₁ ) = D ₁ / 2 = 2.2 cm ³ / 2 = 1.1 cm ³

Lub vojvoog kawg (r2 ₎ = D2 _/ 2 = 2.8 cm3 ^/ 2 = 1.4 ^cm3

Qhov ntim pib (V ₁ ) = 4/3 π r ₁ ³ = (4/3)(3.14)(1.1 cm) ³ = (4/3)(3.14)(1.331 cm ³ ) = 5.57 cm ³

Qhov ntim kawg (V ₂ ) = 4/3 π r ₂ ³ = (4/3)(3.14)(1.4 cm) ³ = (4/3)(3.14)(2.744 cm ³ ) = 11.48 cm ³

Qhov kev hloov pauv ntawm qhov ntim ( Δ V) = 11.48 cm ³ – 5.57 cm ³ = 5.91 cm ³

Xav tau: Qhov kub _kawg ( T2 )

Tshuaj:

Δ V = β (V1 ₎ ( ΔT )

5.91 cm³ = (27 x 10^{-6 o}C^-1)(5.57 cm³)(T₂ - 20^oC)

5.91 = (150.39 x 10 ^-6 ) (T ₂ – 20)

5.91 / 150.39 x 10 ^-6 = T ₂ – 20

0.039 x 10 ⁶ = T ₂ – 20

39 x 10 ³ = T ₂ – 20

39,000 = T ₂ – 20

39,000 + 20 = T ₂

T2 = 39,020 ^oC_​

3. Ib qho 2000-cm³ thawv txhuas, puv nrog dej ntawm 0^oC. Thiab tom qab ntawd cua sov rau 90^oC. Yog tias tus coefficient ntawm linear expansion rau txhuas yog 24 x 10^-6 (^oC)^-1 thiab tus coefficient ntawm qhov ntim nthuav dav rau dej yog 6.3 x 10^-4 (^oC)^-1, txiav txim siab qhov ntim ntawm cov dej nchuav.

Paub:

Qhov ntim pib ntawm lub thawv txhuas thiab dej (Vo ⁾ ₌ 2000 cm3 ⁼ 2 x ¹⁰³ cm3

Qhov kub pib ntawm lub thawv txhuas thiab dej (T1 ₎ = 0 ^o C

Qhov kub kawg ntawm lub thawv txhuas thiab dej (T2 ₎ = 90 ^o C

Tus coefficient ntawm linear expansion rau txhuas (α) = 24 x 10 ^-6 ( ^oC ) ^-1

Tus coefficient ntawm kev nthuav dav rau txhuas (γ) = 3α = 3 (24 x 10 ^{-6 (} oC ⁾ -1 ⁾ = 72 x 10 ^{-6 oC} -1

Tus coefficient ntawm qhov ntim nthuav dav rau dej (γ) = 6.3 x 10 ^-4 ( ^oC ) ^-1

Xav tau: Qhov ntim ntawm cov dej ntws tawm

Tshuaj:

Cov qauv ntawm qhov ntim nthuav dav:

V = _V₂O + γ V₂O _ΔT

V – _Vo = γ Vo _ΔT

ΔV = γ V _o ΔT

V = qhov ntim kawg, V ₌ qhov ntim pib, ΔV = qhov kev hloov pauv ntawm qhov ntim, γ = tus coefficient ntawm kev nthuav dav ntawm qhov ntim, ΔT = qhov kev hloov pauv ntawm qhov kub thiab txias

Xam qhov kev hloov pauv ntawm qhov ntim ntawm lub thawv txhuas:

ΔV = γ V _o ΔT = (72 x 10 ^-6 )(2 x 10 ³ )(90) = 12960 x 10 ^-3 = 12.960 cm ³

Xam qhov kev hloov pauv ntawm qhov ntim ntawm dej:

ΔV = γ V _o ΔT = (6.3 x 10 ^-4 )(2 x 10 ³ )(90) = 1134 x 10 ^-1 = 113.4 ^cm3

Qhov kev hloov pauv ntawm cov dej ntim ntau dua li lub thawv txhuas ua rau qee cov dej nchuav.

Xam qhov ntim ntawm cov dej nchuav:

113.4 cm ³ – 12.960 cm ³ = 100.44 cm ³

[wpdm_package id='702′]

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. Thaum 20 ^o C, qhov ntev ntawm daim hlau yog 50 cm thiab qhov dav yog 30 cm. Yog tias tus coefficient ntawm linear expansion rau hlau yog 10 ^{-5 o} C ^-1 , txiav txim siab qhov kev hloov pauv ntawm thaj chaw thiab thaj chaw kawg ntawm 60 ^o C.

Paub:

Qhov kub pib (T ₁ ) = 20 ^o C

Qhov kub kawg (T2 ₎ = 60 ^o C

Qhov kev hloov pauv ntawm qhov kub thiab txias ( ΔT ) = 60 ^o C – 20 ^o C = 40 ^o C

Thaj chaw pib (A ₁ ) = ntev x dav = 50 cm x 30 cm = 1500 cm ²

Tus coefficient ntawm linear expansion rau hlau ( α) = 10 ^{-5 o} C ^-1

Tus coefficient ntawm thaj chaw nthuav dav rau hlau ( β) = 2α = 2 x 10 ^{-5 o} C ^-1

Xav tau: Qhov kev hloov pauv hauv cheeb tsam ( ΔA )

Tshuaj:

Qhov kev hloov pauv hauv cheeb tsam ( ΔA ):

ΔA = βA ₁ ΔT

ΔA = ( 2 x 10 ^{-5 o} C ^-1 )(1500 cm2 )(40 ^{o C} )

Luas = 80 x 10 ^{- 5} (1500 cm ² )

^ΔA = 1 20,000 x 10 ^-5 cm2

Luas = 1.2 x 10 ⁵ x 10 ^-5 cm ²

ΔA = ^1.2 cm2

Thaj chaw kawg ( A ₂ ):

A2 = _A1 + ΔA_​

A ₂ = 1500 cm ² + 1. 2 cm ²

A ₂ = 1501 . 2 cm ²

2. Thaum 30 ^o C, thaj tsam ntawm ib daim ntawv txhuas yog 40 cm ² thiab tus coefficient ntawm linear expansion yog 24 x 10 ^-6 / ^o C. Txheeb xyuas qhov kub kawg yog tias thaj tsam kawg yog 40.2 cm ².

Paub:

Qhov kub pib (T ₁ ) = 30 ^o C

Tus coefficient ntawm linear expansion ( α) = 24 x 10 ^{-6 o} C ^-1

Tus coefficient ntawm thaj chaw nthuav dav ( β) = 2a = 2 x 24 x 10 ^{-6 o} C ^-1 = 48 x 10 ^{-6 o} C ^-1

Thaj chaw pib (A ₁ ) = 40 cm ²

Thaj chaw kawg (A ₂ ) = 40.2 cm ²

Qhov kev hloov pauv ntawm thaj chaw ( ΔA) = 40.2 cm ² – 40 cm ² = 0.2 cm ²

Xav tau: Txheeb xyuas qhov kub kawg (T ₂ )

Tshuaj:

Cov mis ntawm qhov kev hloov pauv hauv cheeb tsam ( ΔA) :

ΔA = β A ₁ Δ T

Qhov kub kawg (T ₂ ):

ΔA = β A1 ( _T2 – _T1 )_​

0.2 cm² = (48 x 10^{-6 o}C^-1)(40 cm²)(T₂ - 30^oC)

0.2 = (1920 x 10 ^-6 ) (T ₂ – 30 )

0.2 = (1.920 x 10 ^-3 ) (T ₂ – 30)

0.2 = (2 x 10 ^-3 ) (T ₂ – 30)

0.2 / (2 x 10 ^-3 ) = T ₂ – 30

0.1 x 10 ³ = T ₂ – 30

1 x 10 ² = T ₂ – 30

100 = T ₂ – 30

100 + 30 = T ₂

T ₂ = 130

Qhov kub kawg = 130 ^o C

3. Lub vojvoog ntawm lub nplhaib ntawm 20 ^o C yog 20 cm. Yog tias lub vojvoog kawg ntawm 100 ^o C yog 20.5 cm, txiav txim siab qhov coefficient ntawm thaj chaw nthuav dav thiab qhov coefficient ntawm kev nthuav dav linear ...

Paub:

Qhov kub pib (T ₁ ) = 30 ^o C

Qhov kub kawg (T2 ₎ = 100 ^o C

Qhov kev hloov pauv ntawm qhov kub thiab txias ( ΔT ) = 100 ^o C – 30 ^o C = 70 ^o C

Lub vojvoog pib (r ₁ ) = 20 cm

Lub vojvoog kawg (r ₂ ) = 20.5 cm

Xav tau: Tus coefficient ntawm thaj chaw nthuav dav ( β )

Tshuaj:

Thaj chaw pib (A ₁ ) = π r ₁ ² = (3.14)(20 cm) ² = (3.14)(400 cm ² ) = 1256 cm ²

Thaj chaw kawg (A2 ₎ = πr22 = ₍ 3.14 )(20.5 cm) ^{2 =} (3.14)(420.25 cm2 ⁾ = 1319.585 ^cm2

Qhov kev hloov pauv ntawm thaj chaw ( ΔA) = 1319.585 cm ² – 1256 cm ² = 63.585 cm ²

Cov mis ntawm qhov kev hloov pauv hauv cheeb tsam ( ΔA) :

ΔA = βA ₁ ΔT

Tus coefficient ntawm thaj chaw nthuav dav:

ΔA = βA ₁ ΔT

63.585 cm2 ⁼ b (1 256 cm2 ⁾ (70 ^o C)

63.585 = b ( 87,920 ^o C )

β = 63.585 / 87,920 ^o C

β = 0.00072 / ^o C

β = 7.2 x 1 0 ^-4 / ^o C

β = 7.2 x 1 0 ^{-4 o} C ^-1

Tus coefficient ntawm linear expansion ( α ):

β = 2 α

α = β / 2

α = (7.2 x 10 -4 ⁾ / 2

α = 3.6 x 1 0 ^{-4 o} C ^-1

[wpdm_package id='698′]

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